diff --git a/src/GraphQLParser.ApiTests/GraphQLParser.approved.txt b/src/GraphQLParser.ApiTests/GraphQLParser.approved.txt
index 1ab610ae..2f450a14 100644
--- a/src/GraphQLParser.ApiTests/GraphQLParser.approved.txt
+++ b/src/GraphQLParser.ApiTests/GraphQLParser.approved.txt
@@ -138,6 +138,12 @@ namespace GraphQLParser.AST
         public GraphQLArgumentsDefinition() { }
         public override GraphQLParser.AST.ASTNodeKind Kind { get; }
     }
+    public class GraphQLBooleanValue : GraphQLParser.AST.GraphQLValue
+    {
+        public GraphQLBooleanValue() { }
+        public override GraphQLParser.AST.ASTNodeKind Kind { get; }
+        public GraphQLParser.ROM Value { get; set; }
+    }
     public class GraphQLComment : GraphQLParser.AST.ASTNode
     {
         public GraphQLComment() { }
@@ -199,10 +205,17 @@ namespace GraphQLParser.AST
         public override GraphQLParser.AST.ASTNodeKind Kind { get; }
         public GraphQLParser.AST.GraphQLEnumValuesDefinition? Values { get; set; }
     }
+    public class GraphQLEnumValue : GraphQLParser.AST.GraphQLValue, GraphQLParser.AST.INamedNode
+    {
+        public GraphQLEnumValue() { }
+        public override GraphQLParser.AST.ASTNodeKind Kind { get; }
+        public GraphQLParser.AST.GraphQLName Name { get; set; }
+    }
     public class GraphQLEnumValueDefinition : GraphQLParser.AST.GraphQLTypeDefinition, GraphQLParser.AST.IHasDirectivesNode
     {
         public GraphQLEnumValueDefinition() { }
         public GraphQLParser.AST.GraphQLDirectives? Directives { get; set; }
+        public GraphQLParser.AST.GraphQLEnumValue EnumValue { get; set; }
         public override GraphQLParser.AST.ASTNodeKind Kind { get; }
     }
     public class GraphQLEnumValuesDefinition : GraphQLParser.AST.ASTListNode<GraphQLParser.AST.GraphQLEnumValueDefinition>
@@ -239,6 +252,12 @@ namespace GraphQLParser.AST
         public GraphQLFieldsDefinition() { }
         public override GraphQLParser.AST.ASTNodeKind Kind { get; }
     }
+    public class GraphQLFloatValue : GraphQLParser.AST.GraphQLValue
+    {
+        public GraphQLFloatValue() { }
+        public override GraphQLParser.AST.ASTNodeKind Kind { get; }
+        public GraphQLParser.ROM Value { get; set; }
+    }
     public class GraphQLFragmentDefinition : GraphQLParser.AST.GraphQLExecutableDefinition, GraphQLParser.AST.INamedNode
     {
         public GraphQLFragmentDefinition() { }
@@ -293,6 +312,12 @@ namespace GraphQLParser.AST
         public override GraphQLParser.AST.ASTNodeKind Kind { get; }
         public GraphQLParser.AST.GraphQLType Type { get; set; }
     }
+    public class GraphQLIntValue : GraphQLParser.AST.GraphQLValue
+    {
+        public GraphQLIntValue() { }
+        public override GraphQLParser.AST.ASTNodeKind Kind { get; }
+        public GraphQLParser.ROM Value { get; set; }
+    }
     public class GraphQLInterfaceTypeDefinition : GraphQLParser.AST.GraphQLTypeDefinition, GraphQLParser.AST.IHasDirectivesNode, GraphQLParser.AST.IHasFieldsDefinitionNode, GraphQLParser.AST.IHasInterfacesNode
     {
         public GraphQLInterfaceTypeDefinition() { }
@@ -356,12 +381,18 @@ namespace GraphQLParser.AST
         public GraphQLParser.AST.GraphQLType Type { get; set; }
         public override string ToString() { }
     }
+    public class GraphQLNullValue : GraphQLParser.AST.GraphQLValue
+    {
+        public GraphQLNullValue() { }
+        public override GraphQLParser.AST.ASTNodeKind Kind { get; }
+        public GraphQLParser.ROM Value { get; set; }
+    }
     public class GraphQLObjectField : GraphQLParser.AST.ASTNode, GraphQLParser.AST.INamedNode
     {
         public GraphQLObjectField() { }
         public override GraphQLParser.AST.ASTNodeKind Kind { get; }
         public GraphQLParser.AST.GraphQLName Name { get; set; }
-        public GraphQLParser.AST.GraphQLValue? Value { get; set; }
+        public GraphQLParser.AST.GraphQLValue Value { get; set; }
     }
     public class GraphQLObjectTypeDefinition : GraphQLParser.AST.GraphQLTypeDefinition, GraphQLParser.AST.IHasDirectivesNode, GraphQLParser.AST.IHasFieldsDefinitionNode, GraphQLParser.AST.IHasInterfacesNode
     {
@@ -412,13 +443,6 @@ namespace GraphQLParser.AST
         public GraphQLParser.AST.GraphQLDirectives? Directives { get; set; }
         public override GraphQLParser.AST.ASTNodeKind Kind { get; }
     }
-    public class GraphQLScalarValue : GraphQLParser.AST.GraphQLValue
-    {
-        public GraphQLScalarValue(GraphQLParser.AST.ASTNodeKind kind) { }
-        public override GraphQLParser.AST.ASTNodeKind Kind { get; }
-        public GraphQLParser.ROM Value { get; set; }
-        public override string? ToString() { }
-    }
     public class GraphQLSchemaDefinition : GraphQLParser.AST.ASTNode, GraphQLParser.AST.IHasDescriptionNode, GraphQLParser.AST.IHasDirectivesNode
     {
         public GraphQLSchemaDefinition() { }
@@ -433,6 +457,12 @@ namespace GraphQLParser.AST
         public override GraphQLParser.AST.ASTNodeKind Kind { get; }
         public System.Collections.Generic.List<GraphQLParser.AST.ASTNode>? Selections { get; set; }
     }
+    public class GraphQLStringValue : GraphQLParser.AST.GraphQLValue
+    {
+        public GraphQLStringValue() { }
+        public override GraphQLParser.AST.ASTNodeKind Kind { get; }
+        public GraphQLParser.ROM Value { get; set; }
+    }
     public abstract class GraphQLType : GraphQLParser.AST.ASTNode
     {
         protected GraphQLType() { }
@@ -681,7 +711,7 @@ namespace GraphQLParser.Visitors
         public virtual System.Threading.Tasks.ValueTask VisitArgument(GraphQLParser.AST.GraphQLArgument argument, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitArguments(GraphQLParser.AST.GraphQLArguments arguments, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitArgumentsDefinition(GraphQLParser.AST.GraphQLArgumentsDefinition argumentsDefinition, TContext context) { }
-        public virtual System.Threading.Tasks.ValueTask VisitBooleanValue(GraphQLParser.AST.GraphQLScalarValue booleanValue, TContext context) { }
+        public virtual System.Threading.Tasks.ValueTask VisitBooleanValue(GraphQLParser.AST.GraphQLBooleanValue booleanValue, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitComment(GraphQLParser.AST.GraphQLComment comment, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitDescription(GraphQLParser.AST.GraphQLDescription description, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitDirective(GraphQLParser.AST.GraphQLDirective directive, TContext context) { }
@@ -691,13 +721,13 @@ namespace GraphQLParser.Visitors
         public virtual System.Threading.Tasks.ValueTask VisitDocument(GraphQLParser.AST.GraphQLDocument document, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitEnumTypeDefinition(GraphQLParser.AST.GraphQLEnumTypeDefinition enumTypeDefinition, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitEnumTypeExtension(GraphQLParser.AST.GraphQLEnumTypeExtension enumTypeExtension, TContext context) { }
-        public virtual System.Threading.Tasks.ValueTask VisitEnumValue(GraphQLParser.AST.GraphQLScalarValue enumValue, TContext context) { }
+        public virtual System.Threading.Tasks.ValueTask VisitEnumValue(GraphQLParser.AST.GraphQLEnumValue enumValue, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitEnumValueDefinition(GraphQLParser.AST.GraphQLEnumValueDefinition enumValueDefinition, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitEnumValuesDefinition(GraphQLParser.AST.GraphQLEnumValuesDefinition enumValuesDefinition, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitField(GraphQLParser.AST.GraphQLField field, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitFieldDefinition(GraphQLParser.AST.GraphQLFieldDefinition fieldDefinition, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitFieldsDefinition(GraphQLParser.AST.GraphQLFieldsDefinition fieldsDefinition, TContext context) { }
-        public virtual System.Threading.Tasks.ValueTask VisitFloatValue(GraphQLParser.AST.GraphQLScalarValue floatValue, TContext context) { }
+        public virtual System.Threading.Tasks.ValueTask VisitFloatValue(GraphQLParser.AST.GraphQLFloatValue floatValue, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitFragmentDefinition(GraphQLParser.AST.GraphQLFragmentDefinition fragmentDefinition, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitFragmentSpread(GraphQLParser.AST.GraphQLFragmentSpread fragmentSpread, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitImplementsInterfaces(GraphQLParser.AST.GraphQLImplementsInterfaces implementsInterfaces, TContext context) { }
@@ -706,7 +736,7 @@ namespace GraphQLParser.Visitors
         public virtual System.Threading.Tasks.ValueTask VisitInputObjectTypeDefinition(GraphQLParser.AST.GraphQLInputObjectTypeDefinition inputObjectTypeDefinition, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitInputObjectTypeExtension(GraphQLParser.AST.GraphQLInputObjectTypeExtension inputObjectTypeExtension, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitInputValueDefinition(GraphQLParser.AST.GraphQLInputValueDefinition inputValueDefinition, TContext context) { }
-        public virtual System.Threading.Tasks.ValueTask VisitIntValue(GraphQLParser.AST.GraphQLScalarValue intValue, TContext context) { }
+        public virtual System.Threading.Tasks.ValueTask VisitIntValue(GraphQLParser.AST.GraphQLIntValue intValue, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitInterfaceTypeDefinition(GraphQLParser.AST.GraphQLInterfaceTypeDefinition interfaceTypeDefinition, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitInterfaceTypeExtension(GraphQLParser.AST.GraphQLInterfaceTypeExtension interfaceTypeExtension, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitListType(GraphQLParser.AST.GraphQLListType listType, TContext context) { }
@@ -714,7 +744,7 @@ namespace GraphQLParser.Visitors
         public virtual System.Threading.Tasks.ValueTask VisitName(GraphQLParser.AST.GraphQLName name, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitNamedType(GraphQLParser.AST.GraphQLNamedType namedType, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitNonNullType(GraphQLParser.AST.GraphQLNonNullType nonNullType, TContext context) { }
-        public virtual System.Threading.Tasks.ValueTask VisitNullValue(GraphQLParser.AST.GraphQLScalarValue nullValue, TContext context) { }
+        public virtual System.Threading.Tasks.ValueTask VisitNullValue(GraphQLParser.AST.GraphQLNullValue nullValue, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitObjectField(GraphQLParser.AST.GraphQLObjectField objectField, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitObjectTypeDefinition(GraphQLParser.AST.GraphQLObjectTypeDefinition objectTypeDefinition, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitObjectTypeExtension(GraphQLParser.AST.GraphQLObjectTypeExtension objectTypeExtension, TContext context) { }
@@ -725,7 +755,7 @@ namespace GraphQLParser.Visitors
         public virtual System.Threading.Tasks.ValueTask VisitScalarTypeExtension(GraphQLParser.AST.GraphQLScalarTypeExtension scalarTypeExtension, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitSchemaDefinition(GraphQLParser.AST.GraphQLSchemaDefinition schemaDefinition, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitSelectionSet(GraphQLParser.AST.GraphQLSelectionSet selectionSet, TContext context) { }
-        public virtual System.Threading.Tasks.ValueTask VisitStringValue(GraphQLParser.AST.GraphQLScalarValue stringValue, TContext context) { }
+        public virtual System.Threading.Tasks.ValueTask VisitStringValue(GraphQLParser.AST.GraphQLStringValue stringValue, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitTypeCondition(GraphQLParser.AST.GraphQLTypeCondition typeCondition, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitUnionMemberTypes(GraphQLParser.AST.GraphQLUnionMemberTypes unionMemberTypes, TContext context) { }
         public virtual System.Threading.Tasks.ValueTask VisitUnionTypeDefinition(GraphQLParser.AST.GraphQLUnionTypeDefinition unionTypeDefinition, TContext context) { }
@@ -755,7 +785,7 @@ namespace GraphQLParser.Visitors
         System.Threading.Tasks.ValueTask VisitArgument(GraphQLParser.AST.GraphQLArgument argument, TContext context);
         System.Threading.Tasks.ValueTask VisitArguments(GraphQLParser.AST.GraphQLArguments arguments, TContext context);
         System.Threading.Tasks.ValueTask VisitArgumentsDefinition(GraphQLParser.AST.GraphQLArgumentsDefinition argumentsDefinition, TContext context);
-        System.Threading.Tasks.ValueTask VisitBooleanValue(GraphQLParser.AST.GraphQLScalarValue booleanValue, TContext context);
+        System.Threading.Tasks.ValueTask VisitBooleanValue(GraphQLParser.AST.GraphQLBooleanValue booleanValue, TContext context);
         System.Threading.Tasks.ValueTask VisitComment(GraphQLParser.AST.GraphQLComment comment, TContext context);
         System.Threading.Tasks.ValueTask VisitDescription(GraphQLParser.AST.GraphQLDescription description, TContext context);
         System.Threading.Tasks.ValueTask VisitDirective(GraphQLParser.AST.GraphQLDirective directive, TContext context);
@@ -765,13 +795,13 @@ namespace GraphQLParser.Visitors
         System.Threading.Tasks.ValueTask VisitDocument(GraphQLParser.AST.GraphQLDocument document, TContext context);
         System.Threading.Tasks.ValueTask VisitEnumTypeDefinition(GraphQLParser.AST.GraphQLEnumTypeDefinition enumTypeDefinition, TContext context);
         System.Threading.Tasks.ValueTask VisitEnumTypeExtension(GraphQLParser.AST.GraphQLEnumTypeExtension enumTypeExtension, TContext context);
-        System.Threading.Tasks.ValueTask VisitEnumValue(GraphQLParser.AST.GraphQLScalarValue enumValue, TContext context);
+        System.Threading.Tasks.ValueTask VisitEnumValue(GraphQLParser.AST.GraphQLEnumValue enumValue, TContext context);
         System.Threading.Tasks.ValueTask VisitEnumValueDefinition(GraphQLParser.AST.GraphQLEnumValueDefinition enumValueDefinition, TContext context);
         System.Threading.Tasks.ValueTask VisitEnumValuesDefinition(GraphQLParser.AST.GraphQLEnumValuesDefinition enumValuesDefinition, TContext context);
         System.Threading.Tasks.ValueTask VisitField(GraphQLParser.AST.GraphQLField field, TContext context);
         System.Threading.Tasks.ValueTask VisitFieldDefinition(GraphQLParser.AST.GraphQLFieldDefinition fieldDefinition, TContext context);
         System.Threading.Tasks.ValueTask VisitFieldsDefinition(GraphQLParser.AST.GraphQLFieldsDefinition fieldsDefinition, TContext context);
-        System.Threading.Tasks.ValueTask VisitFloatValue(GraphQLParser.AST.GraphQLScalarValue floatValue, TContext context);
+        System.Threading.Tasks.ValueTask VisitFloatValue(GraphQLParser.AST.GraphQLFloatValue floatValue, TContext context);
         System.Threading.Tasks.ValueTask VisitFragmentDefinition(GraphQLParser.AST.GraphQLFragmentDefinition fragmentDefinition, TContext context);
         System.Threading.Tasks.ValueTask VisitFragmentSpread(GraphQLParser.AST.GraphQLFragmentSpread fragmentSpread, TContext context);
         System.Threading.Tasks.ValueTask VisitImplementsInterfaces(GraphQLParser.AST.GraphQLImplementsInterfaces implementsInterfaces, TContext context);
@@ -780,7 +810,7 @@ namespace GraphQLParser.Visitors
         System.Threading.Tasks.ValueTask VisitInputObjectTypeDefinition(GraphQLParser.AST.GraphQLInputObjectTypeDefinition inputObjectTypeDefinition, TContext context);
         System.Threading.Tasks.ValueTask VisitInputObjectTypeExtension(GraphQLParser.AST.GraphQLInputObjectTypeExtension inputObjectTypeExtension, TContext context);
         System.Threading.Tasks.ValueTask VisitInputValueDefinition(GraphQLParser.AST.GraphQLInputValueDefinition inputValueDefinition, TContext context);
-        System.Threading.Tasks.ValueTask VisitIntValue(GraphQLParser.AST.GraphQLScalarValue intValue, TContext context);
+        System.Threading.Tasks.ValueTask VisitIntValue(GraphQLParser.AST.GraphQLIntValue intValue, TContext context);
         System.Threading.Tasks.ValueTask VisitInterfaceTypeDefinition(GraphQLParser.AST.GraphQLInterfaceTypeDefinition interfaceTypeDefinition, TContext context);
         System.Threading.Tasks.ValueTask VisitInterfaceTypeExtension(GraphQLParser.AST.GraphQLInterfaceTypeExtension interfaceTypeExtension, TContext context);
         System.Threading.Tasks.ValueTask VisitListType(GraphQLParser.AST.GraphQLListType listType, TContext context);
@@ -788,7 +818,7 @@ namespace GraphQLParser.Visitors
         System.Threading.Tasks.ValueTask VisitName(GraphQLParser.AST.GraphQLName name, TContext context);
         System.Threading.Tasks.ValueTask VisitNamedType(GraphQLParser.AST.GraphQLNamedType namedType, TContext context);
         System.Threading.Tasks.ValueTask VisitNonNullType(GraphQLParser.AST.GraphQLNonNullType nonNullType, TContext context);
-        System.Threading.Tasks.ValueTask VisitNullValue(GraphQLParser.AST.GraphQLScalarValue nullValue, TContext context);
+        System.Threading.Tasks.ValueTask VisitNullValue(GraphQLParser.AST.GraphQLNullValue nullValue, TContext context);
         System.Threading.Tasks.ValueTask VisitObjectField(GraphQLParser.AST.GraphQLObjectField objectField, TContext context);
         System.Threading.Tasks.ValueTask VisitObjectTypeDefinition(GraphQLParser.AST.GraphQLObjectTypeDefinition objectTypeDefinition, TContext context);
         System.Threading.Tasks.ValueTask VisitObjectTypeExtension(GraphQLParser.AST.GraphQLObjectTypeExtension objectTypeExtension, TContext context);
@@ -799,7 +829,7 @@ namespace GraphQLParser.Visitors
         System.Threading.Tasks.ValueTask VisitScalarTypeExtension(GraphQLParser.AST.GraphQLScalarTypeExtension scalarTypeExtension, TContext context);
         System.Threading.Tasks.ValueTask VisitSchemaDefinition(GraphQLParser.AST.GraphQLSchemaDefinition schemaDefinition, TContext context);
         System.Threading.Tasks.ValueTask VisitSelectionSet(GraphQLParser.AST.GraphQLSelectionSet selectionSet, TContext context);
-        System.Threading.Tasks.ValueTask VisitStringValue(GraphQLParser.AST.GraphQLScalarValue stringValue, TContext context);
+        System.Threading.Tasks.ValueTask VisitStringValue(GraphQLParser.AST.GraphQLStringValue stringValue, TContext context);
         System.Threading.Tasks.ValueTask VisitTypeCondition(GraphQLParser.AST.GraphQLTypeCondition typeCondition, TContext context);
         System.Threading.Tasks.ValueTask VisitUnionMemberTypes(GraphQLParser.AST.GraphQLUnionMemberTypes unionMemberTypes, TContext context);
         System.Threading.Tasks.ValueTask VisitUnionTypeDefinition(GraphQLParser.AST.GraphQLUnionTypeDefinition unionTypeDefinition, TContext context);
@@ -828,7 +858,7 @@ namespace GraphQLParser.Visitors
         public override System.Threading.Tasks.ValueTask VisitArgument(GraphQLParser.AST.GraphQLArgument argument, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitArguments(GraphQLParser.AST.GraphQLArguments arguments, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitArgumentsDefinition(GraphQLParser.AST.GraphQLArgumentsDefinition argumentsDefinition, TContext context) { }
-        public override System.Threading.Tasks.ValueTask VisitBooleanValue(GraphQLParser.AST.GraphQLScalarValue booleanValue, TContext context) { }
+        public override System.Threading.Tasks.ValueTask VisitBooleanValue(GraphQLParser.AST.GraphQLBooleanValue booleanValue, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitComment(GraphQLParser.AST.GraphQLComment comment, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitDescription(GraphQLParser.AST.GraphQLDescription description, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitDirective(GraphQLParser.AST.GraphQLDirective directive, TContext context) { }
@@ -838,13 +868,13 @@ namespace GraphQLParser.Visitors
         public override System.Threading.Tasks.ValueTask VisitDocument(GraphQLParser.AST.GraphQLDocument document, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitEnumTypeDefinition(GraphQLParser.AST.GraphQLEnumTypeDefinition enumTypeDefinition, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitEnumTypeExtension(GraphQLParser.AST.GraphQLEnumTypeExtension enumTypeExtension, TContext context) { }
-        public override System.Threading.Tasks.ValueTask VisitEnumValue(GraphQLParser.AST.GraphQLScalarValue enumValue, TContext context) { }
+        public override System.Threading.Tasks.ValueTask VisitEnumValue(GraphQLParser.AST.GraphQLEnumValue enumValue, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitEnumValueDefinition(GraphQLParser.AST.GraphQLEnumValueDefinition enumValueDefinition, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitEnumValuesDefinition(GraphQLParser.AST.GraphQLEnumValuesDefinition enumValuesDefinition, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitField(GraphQLParser.AST.GraphQLField field, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitFieldDefinition(GraphQLParser.AST.GraphQLFieldDefinition fieldDefinition, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitFieldsDefinition(GraphQLParser.AST.GraphQLFieldsDefinition fieldsDefinition, TContext context) { }
-        public override System.Threading.Tasks.ValueTask VisitFloatValue(GraphQLParser.AST.GraphQLScalarValue floatValue, TContext context) { }
+        public override System.Threading.Tasks.ValueTask VisitFloatValue(GraphQLParser.AST.GraphQLFloatValue floatValue, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitFragmentDefinition(GraphQLParser.AST.GraphQLFragmentDefinition fragmentDefinition, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitFragmentSpread(GraphQLParser.AST.GraphQLFragmentSpread fragmentSpread, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitImplementsInterfaces(GraphQLParser.AST.GraphQLImplementsInterfaces implementsInterfaces, TContext context) { }
@@ -853,7 +883,7 @@ namespace GraphQLParser.Visitors
         public override System.Threading.Tasks.ValueTask VisitInputObjectTypeDefinition(GraphQLParser.AST.GraphQLInputObjectTypeDefinition inputObjectTypeDefinition, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitInputObjectTypeExtension(GraphQLParser.AST.GraphQLInputObjectTypeExtension inputObjectTypeExtension, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitInputValueDefinition(GraphQLParser.AST.GraphQLInputValueDefinition inputValueDefinition, TContext context) { }
-        public override System.Threading.Tasks.ValueTask VisitIntValue(GraphQLParser.AST.GraphQLScalarValue intValue, TContext context) { }
+        public override System.Threading.Tasks.ValueTask VisitIntValue(GraphQLParser.AST.GraphQLIntValue intValue, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitInterfaceTypeDefinition(GraphQLParser.AST.GraphQLInterfaceTypeDefinition interfaceTypeDefinition, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitInterfaceTypeExtension(GraphQLParser.AST.GraphQLInterfaceTypeExtension interfaceTypeExtension, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitListType(GraphQLParser.AST.GraphQLListType listType, TContext context) { }
@@ -861,7 +891,7 @@ namespace GraphQLParser.Visitors
         public override System.Threading.Tasks.ValueTask VisitName(GraphQLParser.AST.GraphQLName name, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitNamedType(GraphQLParser.AST.GraphQLNamedType namedType, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitNonNullType(GraphQLParser.AST.GraphQLNonNullType nonNullType, TContext context) { }
-        public override System.Threading.Tasks.ValueTask VisitNullValue(GraphQLParser.AST.GraphQLScalarValue nullValue, TContext context) { }
+        public override System.Threading.Tasks.ValueTask VisitNullValue(GraphQLParser.AST.GraphQLNullValue nullValue, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitObjectField(GraphQLParser.AST.GraphQLObjectField objectField, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitObjectTypeDefinition(GraphQLParser.AST.GraphQLObjectTypeDefinition objectTypeDefinition, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitObjectTypeExtension(GraphQLParser.AST.GraphQLObjectTypeExtension objectTypeExtension, TContext context) { }
@@ -872,7 +902,7 @@ namespace GraphQLParser.Visitors
         public override System.Threading.Tasks.ValueTask VisitScalarTypeExtension(GraphQLParser.AST.GraphQLScalarTypeExtension scalarTypeExtension, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitSchemaDefinition(GraphQLParser.AST.GraphQLSchemaDefinition schemaDefinition, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitSelectionSet(GraphQLParser.AST.GraphQLSelectionSet selectionSet, TContext context) { }
-        public override System.Threading.Tasks.ValueTask VisitStringValue(GraphQLParser.AST.GraphQLScalarValue stringValue, TContext context) { }
+        public override System.Threading.Tasks.ValueTask VisitStringValue(GraphQLParser.AST.GraphQLStringValue stringValue, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitTypeCondition(GraphQLParser.AST.GraphQLTypeCondition typeCondition, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitUnionMemberTypes(GraphQLParser.AST.GraphQLUnionMemberTypes unionMemberTypes, TContext context) { }
         public override System.Threading.Tasks.ValueTask VisitUnionTypeDefinition(GraphQLParser.AST.GraphQLUnionTypeDefinition unionTypeDefinition, TContext context) { }
diff --git a/src/GraphQLParser.Tests/Issue82.cs b/src/GraphQLParser.Tests/Issue82.cs
index 220161e3..47663b93 100644
--- a/src/GraphQLParser.Tests/Issue82.cs
+++ b/src/GraphQLParser.Tests/Issue82.cs
@@ -30,7 +30,7 @@ public void Parse_Named_And_Literal_Variables(IgnoreOptions options)
             var selection = def.SelectionSet.Selections[0].ShouldBeAssignableTo<GraphQLField>();
             selection.Arguments.Count.ShouldBe(2);
             selection.Arguments[0].Value.ShouldBeAssignableTo<GraphQLVariable>().Name.Value.ShouldBe("username");
-            selection.Arguments[1].Value.ShouldBeAssignableTo<GraphQLScalarValue>().Value.ShouldBe("Pete");
+            selection.Arguments[1].Value.ShouldBeAssignableTo<GraphQLStringValue>().Value.ShouldBe("Pete");
         }
     }
 }
diff --git a/src/GraphQLParser.Tests/ParserTests.cs b/src/GraphQLParser.Tests/ParserTests.cs
index 44de7c36..472690ec 100644
--- a/src/GraphQLParser.Tests/ParserTests.cs
+++ b/src/GraphQLParser.Tests/ParserTests.cs
@@ -208,13 +208,13 @@ public void Comments_on_Values_Should_Read_Correctly(IgnoreOptions options)
             field.SelectionSet.Selections.Count.ShouldBe(1);
             field.Arguments.Count.ShouldBe(9);
 
-            var boolValue = field.Arguments[0].Value.ShouldBeAssignableTo<GraphQLScalarValue>();
+            var boolValue = field.Arguments[0].Value.ShouldBeAssignableTo<GraphQLBooleanValue>();
             boolValue.Comment.ShouldNotBeNull().Text.ShouldBe("comment for bool");
 
-            var nullValue = field.Arguments[1].Value.ShouldBeAssignableTo<GraphQLScalarValue>();
+            var nullValue = field.Arguments[1].Value.ShouldBeAssignableTo<GraphQLNullValue>();
             nullValue.Comment.ShouldNotBeNull().Text.ShouldBe("comment for null");
 
-            var enumValue = field.Arguments[2].Value.ShouldBeAssignableTo<GraphQLScalarValue>();
+            var enumValue = field.Arguments[2].Value.ShouldBeAssignableTo<GraphQLEnumValue>();
             enumValue.Comment.ShouldNotBeNull().Text.ShouldBe("comment for enum");
 
             var listValue = field.Arguments[3].Value.ShouldBeAssignableTo<GraphQLListValue>();
@@ -223,13 +223,13 @@ public void Comments_on_Values_Should_Read_Correctly(IgnoreOptions options)
             var objValue = field.Arguments[4].Value.ShouldBeAssignableTo<GraphQLObjectValue>();
             objValue.Comment.ShouldNotBeNull().Text.ShouldBe("comment for object");
 
-            var intValue = field.Arguments[5].Value.ShouldBeAssignableTo<GraphQLScalarValue>();
+            var intValue = field.Arguments[5].Value.ShouldBeAssignableTo<GraphQLIntValue>();
             intValue.Comment.ShouldNotBeNull().Text.ShouldBe("comment for int");
 
-            var floatValue = field.Arguments[6].Value.ShouldBeAssignableTo<GraphQLScalarValue>();
+            var floatValue = field.Arguments[6].Value.ShouldBeAssignableTo<GraphQLFloatValue>();
             floatValue.Comment.ShouldNotBeNull().Text.ShouldBe("comment for float");
 
-            var stringValue = field.Arguments[7].Value.ShouldBeAssignableTo<GraphQLScalarValue>();
+            var stringValue = field.Arguments[7].Value.ShouldBeAssignableTo<GraphQLStringValue>();
             stringValue.Comment.ShouldNotBeNull().Text.ShouldBe("comment for string");
 
             var varValue = field.Arguments[8].Value.ShouldBeAssignableTo<GraphQLVariable>();
@@ -527,6 +527,18 @@ public void Should_Throw_On_Unknown_OperationType()
             ex.Column.ShouldBe(1);
         }
 
+        [Theory]
+        [InlineData("enum E { true A }", "Unexpected Name \"true\"; enum values are represented as unquoted names but not 'true' or 'false' or 'null'.", 1, 10)]
+        [InlineData("enum E { B false }", "Unexpected Name \"false\"; enum values are represented as unquoted names but not 'true' or 'false' or 'null'.", 1, 12)]
+        [InlineData("enum E { A null B }", "Unexpected Name \"null\"; enum values are represented as unquoted names but not 'true' or 'false' or 'null'.", 1, 12)]
+        public void Should_Throw_On_Invalid_EnumValue(string query, string description, int line, int column)
+        {
+            var ex = Should.Throw<GraphQLSyntaxErrorException>(() => query.Parse());
+            ex.Description.ShouldBe(description);
+            ex.Line.ShouldBe(line);
+            ex.Column.ShouldBe(column);
+        }
+
         [Theory]
         [InlineData(IgnoreOptions.None)]
         [InlineData(IgnoreOptions.Comments)]
@@ -825,7 +837,7 @@ public void Should_Parse_SpecifiedBy()
             def.Directives[0].Name.Value.ShouldBe("specifiedBy");
             def.Directives[0].Arguments.Count.ShouldBe(1);
             def.Directives[0].Arguments[0].Name.Value.ShouldBe("url");
-            var value = def.Directives[0].Arguments[0].Value.ShouldBeAssignableTo<GraphQLScalarValue>();
+            var value = def.Directives[0].Arguments[0].Value.ShouldBeAssignableTo<GraphQLStringValue>();
             value.Value.ShouldBe("https://tools.ietf.org/html/rfc4122");
         }
 
@@ -936,23 +948,23 @@ public void Should_Parse_Extensions(string text, ASTNodeKind kind)
         }
 
         [Theory]
-        [InlineData("extend", "Unexpected EOF")]
-        [InlineData("extend scalar", "Expected Name, found EOF")]
-        [InlineData("extend scalar A", "Unexpected EOF")]
-        [InlineData("extend scalar A B", "Unexpected Name \"B\"")]
-        [InlineData("extend type", "Expected Name, found EOF")]
-        [InlineData("extend type A", "Unexpected EOF")]
-        [InlineData("extend type A B", "Unexpected Name \"B\"")]
-        [InlineData("extend interface", "Expected Name, found EOF")]
-        [InlineData("extend interface A", "Unexpected EOF")]
-        [InlineData("extend interface A B", "Unexpected Name \"B\"")]
-        [InlineData("extend union", "Expected Name, found EOF")]
-        [InlineData("extend union A", "Unexpected EOF")]
-        [InlineData("extend enum", "Expected Name, found EOF")]
-        [InlineData("extend enum A", "Unexpected EOF")]
-        [InlineData("extend input", "Expected Name, found EOF")]
-        [InlineData("extend input A", "Unexpected EOF")]
-        [InlineData("extend variable", "Unexpected Name \"variable\"")]
+        [InlineData("extend", "Unexpected EOF; for more information see http://spec.graphql.org/October2021/#TypeExtension")]
+        [InlineData("extend scalar", "Expected Name, found EOF; for more information see http://spec.graphql.org/October2021/#ScalarTypeExtension")]
+        [InlineData("extend scalar A", "Unexpected EOF; for more information see http://spec.graphql.org/October2021/#ScalarTypeExtension")]
+        [InlineData("extend scalar A B", "Unexpected Name \"B\"; for more information see http://spec.graphql.org/October2021/#ScalarTypeExtension")]
+        [InlineData("extend type", "Expected Name, found EOF; for more information see http://spec.graphql.org/October2021/#ObjectTypeExtension")]
+        [InlineData("extend type A", "Unexpected EOF; for more information see http://spec.graphql.org/October2021/#ObjectTypeExtension")]
+        [InlineData("extend type A B", "Unexpected Name \"B\"; for more information see http://spec.graphql.org/October2021/#ObjectTypeExtension")]
+        [InlineData("extend interface", "Expected Name, found EOF; for more information see http://spec.graphql.org/October2021/#InterfaceTypeExtension")]
+        [InlineData("extend interface A", "Unexpected EOF; for more information see http://spec.graphql.org/October2021/#InterfaceTypeExtension")]
+        [InlineData("extend interface A B", "Unexpected Name \"B\"; for more information see http://spec.graphql.org/October2021/#InterfaceTypeExtension")]
+        [InlineData("extend union", "Expected Name, found EOF; for more information see http://spec.graphql.org/October2021/#UnionTypeExtension")]
+        [InlineData("extend union A", "Unexpected EOF; for more information see http://spec.graphql.org/October2021/#UnionTypeExtension")]
+        [InlineData("extend enum", "Expected Name, found EOF; for more information see http://spec.graphql.org/October2021/#EnumTypeExtension")]
+        [InlineData("extend enum A", "Unexpected EOF; for more information see http://spec.graphql.org/October2021/#EnumTypeExtension")]
+        [InlineData("extend input", "Expected Name, found EOF; for more information see http://spec.graphql.org/October2021/#InputObjectTypeExtension")]
+        [InlineData("extend input A", "Unexpected EOF; for more information see http://spec.graphql.org/October2021/#InputObjectTypeExtension")]
+        [InlineData("extend variable", "Unexpected Name \"variable\"; for more information see http://spec.graphql.org/October2021/#TypeExtension")]
         public void Should_Throw_Extensions(string text, string description)
         {
             var ex = Should.Throw<GraphQLSyntaxErrorException>(() => text.Parse());
diff --git a/src/GraphQLParser.Tests/Validation/ParserValidationTests.cs b/src/GraphQLParser.Tests/Validation/ParserValidationTests.cs
index ac1e78a0..cf45eabe 100644
--- a/src/GraphQLParser.Tests/Validation/ParserValidationTests.cs
+++ b/src/GraphQLParser.Tests/Validation/ParserValidationTests.cs
@@ -16,10 +16,10 @@ public void Parse_FragmentInvalidOnName_ThrowsExceptionWithCorrectMessage(Ignore
             var exception = Should.Throw<GraphQLSyntaxErrorException>(() => "fragment on on on { on }".Parse(new ParserOptions { Ignore = options }));
 
             exception.Message.ShouldBe(
-                "Syntax Error GraphQL (1:10) Unexpected Name \"on\"\n" +
+                "Syntax Error GraphQL (1:10) Unexpected Name \"on\"; fragment name can not be 'on'.\n" +
                 "1: fragment on on on { on }\n" +
                 "            ^\n");
-            exception.Description.ShouldBe("Unexpected Name " + "\"on\"");
+            exception.Description.ShouldBe("Unexpected Name " + "\"on\"; fragment name can not be 'on'.");
             exception.Line.ShouldBe(1);
             exception.Column.ShouldBe(10);
         }
@@ -52,10 +52,10 @@ public void Parse_InvalidFragmentNameInSpread_ThrowsExceptionWithCorrectMessage(
             var exception = Should.Throw<GraphQLSyntaxErrorException>(() => "{ ...on }".Parse(new ParserOptions { Ignore = options }));
 
             exception.Message.ShouldBe(
-                "Syntax Error GraphQL (1:9) Expected Name, found }\n" +
+                "Syntax Error GraphQL (1:9) Expected Name, found }; for more information see http://spec.graphql.org/October2021/#NamedType\n" +
                 "1: { ...on }\n" +
                 "           ^\n");
-            exception.Description.ShouldBe("Expected Name, found }");
+            exception.Description.ShouldBe("Expected Name, found }; for more information see http://spec.graphql.org/October2021/#NamedType");
             exception.Line.ShouldBe(1);
             exception.Column.ShouldBe(9);
         }
@@ -88,10 +88,10 @@ public void Parse_MissingEndingBrace_ThrowsExceptionWithCorrectMessage(IgnoreOpt
             var exception = Should.Throw<GraphQLSyntaxErrorException>(() => "{".Parse(new ParserOptions { Ignore = options }));
 
             exception.Message.ShouldBe(
-                "Syntax Error GraphQL (1:2) Expected Name, found EOF\n" +
+                "Syntax Error GraphQL (1:2) Expected Name, found EOF; for more information see http://spec.graphql.org/October2021/#Field\n" +
                 "1: {\n" +
                 "    ^\n");
-            exception.Description.ShouldBe("Expected Name, found EOF");
+            exception.Description.ShouldBe("Expected Name, found EOF; for more information see http://spec.graphql.org/October2021/#Field");
             exception.Line.ShouldBe(1);
             exception.Column.ShouldBe(2);
         }
@@ -106,10 +106,10 @@ public void Parse_MissingFieldNameWhenAliasing_ThrowsExceptionWithCorrectMessage
             var exception = Should.Throw<GraphQLSyntaxErrorException>(() => "{ field: {} }".Parse(new ParserOptions { Ignore = options }));
 
             exception.Message.ShouldBe(
-                "Syntax Error GraphQL (1:10) Expected Name, found {\n" +
+                "Syntax Error GraphQL (1:10) Expected Name, found {; for more information see http://spec.graphql.org/October2021/#Field\n" +
                 "1: { field: {} }\n" +
                 "            ^\n");
-            exception.Description.ShouldBe("Expected Name, found {");
+            exception.Description.ShouldBe("Expected Name, found {; for more information see http://spec.graphql.org/October2021/#Field");
             exception.Line.ShouldBe(1);
             exception.Column.ShouldBe(10);
         }
diff --git a/src/GraphQLParser.Tests/Visitors/GraphQLAstVisitorTests.cs b/src/GraphQLParser.Tests/Visitors/GraphQLAstVisitorTests.cs
index cdaa2586..545667bd 100644
--- a/src/GraphQLParser.Tests/Visitors/GraphQLAstVisitorTests.cs
+++ b/src/GraphQLParser.Tests/Visitors/GraphQLAstVisitorTests.cs
@@ -13,13 +13,13 @@ public class GraphQLAstVisitorTests
     {
         public class CountVisitor : DefaultNodeVisitor<CountContext>
         {
-            public override async ValueTask VisitBooleanValue(GraphQLScalarValue booleanValue, CountContext context)
+            public override async ValueTask VisitBooleanValue(GraphQLBooleanValue booleanValue, CountContext context)
             {
                 context.VisitedBooleanValues.Add(booleanValue);
                 await base.VisitBooleanValue(booleanValue, context);
             }
 
-            public override async ValueTask VisitIntValue(GraphQLScalarValue intValue, CountContext context)
+            public override async ValueTask VisitIntValue(GraphQLIntValue intValue, CountContext context)
             {
                 context.VisitedIntValues.Add(intValue);
                 await base.VisitIntValue(intValue, context);
@@ -55,13 +55,13 @@ public override async ValueTask VisitDirective(GraphQLDirective directive, Count
                 await base.VisitDirective(directive, context);
             }
 
-            public override async ValueTask VisitEnumValue(GraphQLScalarValue enumValue, CountContext context)
+            public override async ValueTask VisitEnumValue(GraphQLEnumValue enumValue, CountContext context)
             {
                 context.VisitedEnumValues.Add(enumValue);
                 await base.VisitEnumValue(enumValue, context);
             }
 
-            public override async ValueTask VisitStringValue(GraphQLScalarValue stringValue, CountContext context)
+            public override async ValueTask VisitStringValue(GraphQLStringValue stringValue, CountContext context)
             {
                 context.VisitedStringValues.Add(stringValue);
                 await base.VisitStringValue(stringValue, context);
@@ -81,7 +81,7 @@ public override async ValueTask VisitField(GraphQLField field, CountContext cont
                 await base.VisitField(field, context);
             }
 
-            public override async ValueTask VisitFloatValue(GraphQLScalarValue floatValue, CountContext context)
+            public override async ValueTask VisitFloatValue(GraphQLFloatValue floatValue, CountContext context)
             {
                 context.VisitedFloatValues.Add(floatValue);
                 await base.VisitFloatValue(floatValue, context);
@@ -192,19 +192,19 @@ public class CountContext : INodeVisitorContext
             public List<GraphQLArgument> VisitedArguments = new();
             public List<ASTNode> VisitedDefinitions = new();
             public List<GraphQLDirective> VisitedDirectives = new();
-            public List<GraphQLScalarValue> VisitedEnumValues = new();
+            public List<GraphQLEnumValue> VisitedEnumValues = new();
             public List<GraphQLField> VisitedFields = new();
-            public List<GraphQLScalarValue> VisitedFloatValues = new();
+            public List<GraphQLFloatValue> VisitedFloatValues = new();
             public List<GraphQLFragmentDefinition> VisitedFragmentDefinitions = new();
             public List<GraphQLFragmentSpread> VisitedFragmentSpreads = new();
             public List<GraphQLTypeCondition> VisitedFragmentTypeConditions = new();
             public List<GraphQLInlineFragment> VisitedInlineFragments = new();
-            public List<GraphQLScalarValue> VisitedIntValues = new();
+            public List<GraphQLIntValue> VisitedIntValues = new();
             public List<GraphQLName> VisitedNames = new();
             public List<GraphQLSelectionSet> VisitedSelectionSets = new();
-            public List<GraphQLScalarValue> VisitedStringValues = new();
+            public List<GraphQLStringValue> VisitedStringValues = new();
             public List<GraphQLVariable> VisitedVariables = new();
-            public List<GraphQLScalarValue> VisitedBooleanValues = new();
+            public List<GraphQLBooleanValue> VisitedBooleanValues = new();
 
             public CancellationToken CancellationToken { get; set; }
         }
diff --git a/src/GraphQLParser/AST/GraphQLBooleanValue.cs b/src/GraphQLParser/AST/GraphQLBooleanValue.cs
new file mode 100644
index 00000000..1a00ff7a
--- /dev/null
+++ b/src/GraphQLParser/AST/GraphQLBooleanValue.cs
@@ -0,0 +1,56 @@
+namespace GraphQLParser.AST
+{
+    /// <summary>
+    /// AST node for <see cref="ASTNodeKind.BooleanValue"/>.
+    /// </summary>
+    public class GraphQLBooleanValue : GraphQLValue
+    {
+        /// <inheritdoc/>
+        public override ASTNodeKind Kind => ASTNodeKind.BooleanValue;
+
+        /// <summary>
+        /// Value represented as <see cref="ROM"/>.
+        /// </summary>
+        public ROM Value { get; set; }
+    }
+
+    internal sealed class GraphQLBooleanValueWithLocation : GraphQLBooleanValue
+    {
+        private GraphQLLocation _location;
+
+        public override GraphQLLocation Location
+        {
+            get => _location;
+            set => _location = value;
+        }
+    }
+
+    internal sealed class GraphQLBooleanValueWithComment : GraphQLBooleanValue
+    {
+        private GraphQLComment? _comment;
+
+        public override GraphQLComment? Comment
+        {
+            get => _comment;
+            set => _comment = value;
+        }
+    }
+
+    internal sealed class GraphQLBooleanValueFull : GraphQLBooleanValue
+    {
+        private GraphQLLocation _location;
+        private GraphQLComment? _comment;
+
+        public override GraphQLLocation Location
+        {
+            get => _location;
+            set => _location = value;
+        }
+
+        public override GraphQLComment? Comment
+        {
+            get => _comment;
+            set => _comment = value;
+        }
+    }
+}
diff --git a/src/GraphQLParser/AST/GraphQLEnumValue.cs b/src/GraphQLParser/AST/GraphQLEnumValue.cs
new file mode 100644
index 00000000..a9681888
--- /dev/null
+++ b/src/GraphQLParser/AST/GraphQLEnumValue.cs
@@ -0,0 +1,54 @@
+namespace GraphQLParser.AST
+{
+    /// <summary>
+    /// AST node for <see cref="ASTNodeKind.EnumValue"/>.
+    /// </summary>
+    public class GraphQLEnumValue : GraphQLValue, INamedNode
+    {
+        /// <inheritdoc/>
+        public override ASTNodeKind Kind => ASTNodeKind.EnumValue;
+
+        /// <inheritdoc/>
+        public GraphQLName Name { get; set; } = null!;
+    }
+
+    internal sealed class GraphQLEnumValueWithLocation : GraphQLEnumValue
+    {
+        private GraphQLLocation _location;
+
+        public override GraphQLLocation Location
+        {
+            get => _location;
+            set => _location = value;
+        }
+    }
+
+    internal sealed class GraphQLEnumValueWithComment : GraphQLEnumValue
+    {
+        private GraphQLComment? _comment;
+
+        public override GraphQLComment? Comment
+        {
+            get => _comment;
+            set => _comment = value;
+        }
+    }
+
+    internal sealed class GraphQLEnumValueFull : GraphQLEnumValue
+    {
+        private GraphQLLocation _location;
+        private GraphQLComment? _comment;
+
+        public override GraphQLLocation Location
+        {
+            get => _location;
+            set => _location = value;
+        }
+
+        public override GraphQLComment? Comment
+        {
+            get => _comment;
+            set => _comment = value;
+        }
+    }
+}
diff --git a/src/GraphQLParser/AST/GraphQLEnumValueDefinition.cs b/src/GraphQLParser/AST/GraphQLEnumValueDefinition.cs
index 778dc6de..c328ec08 100644
--- a/src/GraphQLParser/AST/GraphQLEnumValueDefinition.cs
+++ b/src/GraphQLParser/AST/GraphQLEnumValueDefinition.cs
@@ -8,6 +8,13 @@ public class GraphQLEnumValueDefinition : GraphQLTypeDefinition, IHasDirectivesN
         /// <inheritdoc/>
         public override ASTNodeKind Kind => ASTNodeKind.EnumValueDefinition;
 
+        /// <summary>
+        /// Enum value represented as a nested AST node. Alas, inherited
+        /// <see cref="GraphQLTypeDefinition.Name"/> property holds almost
+        /// the same data and should be set as well.
+        /// </summary>
+        public GraphQLEnumValue EnumValue { get; set; } = null!;
+
         /// <inheritdoc/>
         public GraphQLDirectives? Directives { get; set; }
     }
diff --git a/src/GraphQLParser/AST/GraphQLExecutableDefinition.cs b/src/GraphQLParser/AST/GraphQLExecutableDefinition.cs
index 29135e46..d5a8077f 100644
--- a/src/GraphQLParser/AST/GraphQLExecutableDefinition.cs
+++ b/src/GraphQLParser/AST/GraphQLExecutableDefinition.cs
@@ -2,6 +2,7 @@ namespace GraphQLParser.AST
 {
     /// <summary>
     /// Base AST node for <see cref="GraphQLOperationDefinition"/> and <see cref="GraphQLFragmentDefinition"/>.
+    /// <br/>
     /// http://spec.graphql.org/October2021/#ExecutableDefinition
     /// </summary>
     public abstract class GraphQLExecutableDefinition : ASTNode, IHasDirectivesNode
diff --git a/src/GraphQLParser/AST/GraphQLFloatValue.cs b/src/GraphQLParser/AST/GraphQLFloatValue.cs
new file mode 100644
index 00000000..629ad9e4
--- /dev/null
+++ b/src/GraphQLParser/AST/GraphQLFloatValue.cs
@@ -0,0 +1,56 @@
+namespace GraphQLParser.AST
+{
+    /// <summary>
+    /// AST node for <see cref="ASTNodeKind.BooleanValue"/>.
+    /// </summary>
+    public class GraphQLFloatValue : GraphQLValue
+    {
+        /// <inheritdoc/>
+        public override ASTNodeKind Kind => ASTNodeKind.BooleanValue;
+
+        /// <summary>
+        /// Value represented as <see cref="ROM"/>.
+        /// </summary>
+        public ROM Value { get; set; }
+    }
+
+    internal sealed class GraphQLFloatValueWithLocation : GraphQLFloatValue
+    {
+        private GraphQLLocation _location;
+
+        public override GraphQLLocation Location
+        {
+            get => _location;
+            set => _location = value;
+        }
+    }
+
+    internal sealed class GraphQLFloatValueWithComment : GraphQLFloatValue
+    {
+        private GraphQLComment? _comment;
+
+        public override GraphQLComment? Comment
+        {
+            get => _comment;
+            set => _comment = value;
+        }
+    }
+
+    internal sealed class GraphQLFloatValueFull : GraphQLFloatValue
+    {
+        private GraphQLLocation _location;
+        private GraphQLComment? _comment;
+
+        public override GraphQLLocation Location
+        {
+            get => _location;
+            set => _location = value;
+        }
+
+        public override GraphQLComment? Comment
+        {
+            get => _comment;
+            set => _comment = value;
+        }
+    }
+}
diff --git a/src/GraphQLParser/AST/GraphQLIntValue.cs b/src/GraphQLParser/AST/GraphQLIntValue.cs
new file mode 100644
index 00000000..ba200d85
--- /dev/null
+++ b/src/GraphQLParser/AST/GraphQLIntValue.cs
@@ -0,0 +1,56 @@
+namespace GraphQLParser.AST
+{
+    /// <summary>
+    /// AST node for <see cref="ASTNodeKind.IntValue"/>.
+    /// </summary>
+    public class GraphQLIntValue : GraphQLValue
+    {
+        /// <inheritdoc/>
+        public override ASTNodeKind Kind => ASTNodeKind.IntValue;
+
+        /// <summary>
+        /// Value represented as <see cref="ROM"/>.
+        /// </summary>
+        public ROM Value { get; set; }
+    }
+
+    internal sealed class GraphQLIntValueWithLocation : GraphQLIntValue
+    {
+        private GraphQLLocation _location;
+
+        public override GraphQLLocation Location
+        {
+            get => _location;
+            set => _location = value;
+        }
+    }
+
+    internal sealed class GraphQLIntValueWithComment : GraphQLIntValue
+    {
+        private GraphQLComment? _comment;
+
+        public override GraphQLComment? Comment
+        {
+            get => _comment;
+            set => _comment = value;
+        }
+    }
+
+    internal sealed class GraphQLIntValueFull : GraphQLIntValue
+    {
+        private GraphQLLocation _location;
+        private GraphQLComment? _comment;
+
+        public override GraphQLLocation Location
+        {
+            get => _location;
+            set => _location = value;
+        }
+
+        public override GraphQLComment? Comment
+        {
+            get => _comment;
+            set => _comment = value;
+        }
+    }
+}
diff --git a/src/GraphQLParser/AST/GraphQLNullValue.cs b/src/GraphQLParser/AST/GraphQLNullValue.cs
new file mode 100644
index 00000000..de4117e4
--- /dev/null
+++ b/src/GraphQLParser/AST/GraphQLNullValue.cs
@@ -0,0 +1,56 @@
+namespace GraphQLParser.AST
+{
+    /// <summary>
+    /// AST node for <see cref="ASTNodeKind.NullValue"/>.
+    /// </summary>
+    public class GraphQLNullValue : GraphQLValue
+    {
+        /// <inheritdoc/>
+        public override ASTNodeKind Kind => ASTNodeKind.NullValue;
+
+        /// <summary>
+        /// Value represented as <see cref="ROM"/>.
+        /// </summary>
+        public ROM Value { get; set; }
+    }
+
+    internal sealed class GraphQLNullValueWithLocation : GraphQLNullValue
+    {
+        private GraphQLLocation _location;
+
+        public override GraphQLLocation Location
+        {
+            get => _location;
+            set => _location = value;
+        }
+    }
+
+    internal sealed class GraphQLNullValueWithComment : GraphQLNullValue
+    {
+        private GraphQLComment? _comment;
+
+        public override GraphQLComment? Comment
+        {
+            get => _comment;
+            set => _comment = value;
+        }
+    }
+
+    internal sealed class GraphQLNullValueFull : GraphQLNullValue
+    {
+        private GraphQLLocation _location;
+        private GraphQLComment? _comment;
+
+        public override GraphQLLocation Location
+        {
+            get => _location;
+            set => _location = value;
+        }
+
+        public override GraphQLComment? Comment
+        {
+            get => _comment;
+            set => _comment = value;
+        }
+    }
+}
diff --git a/src/GraphQLParser/AST/GraphQLObjectField.cs b/src/GraphQLParser/AST/GraphQLObjectField.cs
index 56e0fba9..7764282a 100644
--- a/src/GraphQLParser/AST/GraphQLObjectField.cs
+++ b/src/GraphQLParser/AST/GraphQLObjectField.cs
@@ -11,7 +11,7 @@ public class GraphQLObjectField : ASTNode, INamedNode
         /// <inheritdoc/>
         public GraphQLName Name { get; set; } = null!;
 
-        public GraphQLValue? Value { get; set; }
+        public GraphQLValue Value { get; set; } = null!;
     }
 
     internal sealed class GraphQLObjectFieldWithLocation : GraphQLObjectField
diff --git a/src/GraphQLParser/AST/GraphQLScalarValue.cs b/src/GraphQLParser/AST/GraphQLScalarValue.cs
deleted file mode 100644
index 4fae7501..00000000
--- a/src/GraphQLParser/AST/GraphQLScalarValue.cs
+++ /dev/null
@@ -1,102 +0,0 @@
-using System.Diagnostics;
-
-namespace GraphQLParser.AST
-{
-    /// <summary>
-    /// Scalar nodes represent primitive leaf values in a GraphQL document.
-    /// <br/>
-    /// There are 6 kinds of scalar nodes:
-    /// <br/>
-    /// <see cref="ASTNodeKind.StringValue">String</see>
-    /// <br/>
-    /// <see cref="ASTNodeKind.BooleanValue">Boolean</see>
-    /// <br/>
-    /// <see cref="ASTNodeKind.IntValue">Int</see>
-    /// <br/>
-    /// <see cref="ASTNodeKind.FloatValue">Float</see>
-    /// <br/>
-    /// <see cref="ASTNodeKind.EnumValue">Enumeration</see>
-    /// <br/>
-    /// <see cref="ASTNodeKind.NullValue">Null</see>
-    /// </summary>
-    [DebuggerDisplay("{Value}")]
-    public class GraphQLScalarValue : GraphQLValue
-    {
-        private readonly ASTNodeKind _kind;
-
-        /// <summary>
-        /// Creates scalar node with the specified kind.
-        /// </summary>
-        /// <param name="kind">One of six kinds of scalar nodes.</param>
-        public GraphQLScalarValue(ASTNodeKind kind)
-        {
-            _kind = kind;
-        }
-
-        /// <inheritdoc/>
-        public override ASTNodeKind Kind => _kind;
-
-        /// <summary>
-        /// Scalar value represented as <see cref="ROM"/>.
-        /// </summary>
-        public ROM Value { get; set; }
-
-        /// <inheritdoc/>
-        public override string? ToString() => Kind == ASTNodeKind.StringValue ? $"\"{Value}\"" : Value.ToString();
-    }
-
-    internal sealed class GraphQLScalarValueWithLocation : GraphQLScalarValue
-    {
-        private GraphQLLocation _location;
-
-        public GraphQLScalarValueWithLocation(ASTNodeKind kind)
-            : base(kind)
-        {
-        }
-
-        public override GraphQLLocation Location
-        {
-            get => _location;
-            set => _location = value;
-        }
-    }
-
-    internal sealed class GraphQLScalarValueWithComment : GraphQLScalarValue
-    {
-        private GraphQLComment? _comment;
-
-        public GraphQLScalarValueWithComment(ASTNodeKind kind)
-            : base(kind)
-        {
-        }
-
-        public override GraphQLComment? Comment
-        {
-            get => _comment;
-            set => _comment = value;
-        }
-    }
-
-    internal sealed class GraphQLScalarValueFull : GraphQLScalarValue
-    {
-        private GraphQLLocation _location;
-        private GraphQLComment? _comment;
-
-        public GraphQLScalarValueFull(ASTNodeKind kind)
-            : base(kind)
-        {
-        }
-
-        public override GraphQLLocation Location
-        {
-            get => _location;
-            set => _location = value;
-        }
-
-        public override GraphQLComment? Comment
-        {
-            get => _comment;
-            set => _comment = value;
-        }
-    }
-}
diff --git a/src/GraphQLParser/AST/GraphQLStringValue.cs b/src/GraphQLParser/AST/GraphQLStringValue.cs
new file mode 100644
index 00000000..9e4e2136
--- /dev/null
+++ b/src/GraphQLParser/AST/GraphQLStringValue.cs
@@ -0,0 +1,56 @@
+namespace GraphQLParser.AST
+{
+    /// <summary>
+    /// AST node for <see cref="ASTNodeKind.StringValue"/>.
+    /// </summary>
+    public class GraphQLStringValue : GraphQLValue
+    {
+        /// <inheritdoc/>
+        public override ASTNodeKind Kind => ASTNodeKind.StringValue;
+
+        /// <summary>
+        /// Value represented as <see cref="ROM"/>.
+        /// </summary>
+        public ROM Value { get; set; }
+    }
+
+    internal sealed class GraphQLStringValueWithLocation : GraphQLStringValue
+    {
+        private GraphQLLocation _location;
+
+        public override GraphQLLocation Location
+        {
+            get => _location;
+            set => _location = value;
+        }
+    }
+
+    internal sealed class GraphQLStringValueWithComment : GraphQLStringValue
+    {
+        private GraphQLComment? _comment;
+
+        public override GraphQLComment? Comment
+        {
+            get => _comment;
+            set => _comment = value;
+        }
+    }
+
+    internal sealed class GraphQLStringValueFull : GraphQLStringValue
+    {
+        private GraphQLLocation _location;
+        private GraphQLComment? _comment;
+
+        public override GraphQLLocation Location
+        {
+            get => _location;
+            set => _location = value;
+        }
+
+        public override GraphQLComment? Comment
+        {
+            get => _comment;
+            set => _comment = value;
+        }
+    }
+}
diff --git a/src/GraphQLParser/AST/GraphQLValue.cs b/src/GraphQLParser/AST/GraphQLValue.cs
index 8b154e9d..d16e80c2 100644
--- a/src/GraphQLParser/AST/GraphQLValue.cs
+++ b/src/GraphQLParser/AST/GraphQLValue.cs
@@ -1,15 +1,9 @@
 namespace GraphQLParser.AST
 {
     /// <summary>
-    /// Base AST node for four value nodes:
+    /// Base AST node for all value nodes.
     /// <br/>
-    /// <see cref="GraphQLScalarValue">Scalar</see>
-    /// <br/>
-    /// <see cref="ASTNodeKind.ListValue">List</see>
-    /// <br/>
-    /// <see cref="ASTNodeKind.ObjectValue">Object</see>
-    /// <br/>
-    /// <see cref="ASTNodeKind.Variable">Variable</see>
+    /// <see href="http://spec.graphql.org/October2021/#Value"/>
     /// </summary>
     public abstract class GraphQLValue : ASTNode
     {
diff --git a/src/GraphQLParser/NodeHelper.cs b/src/GraphQLParser/NodeHelper.cs
index bcd0e0d2..cbd6b2df 100644
--- a/src/GraphQLParser/NodeHelper.cs
+++ b/src/GraphQLParser/NodeHelper.cs
@@ -95,18 +95,6 @@ public static GraphQLEnumTypeDefinition CreateGraphQLEnumTypeDefinition(IgnoreOp
             };
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static GraphQLScalarValue CreateGraphQLScalarValue(IgnoreOptions options, ASTNodeKind kind)
-        {
-            return options switch
-            {
-                IgnoreOptions.All => new GraphQLScalarValue(kind),
-                IgnoreOptions.Comments => new GraphQLScalarValueWithLocation(kind),
-                IgnoreOptions.Locations => new GraphQLScalarValueWithComment(kind),
-                _ => new GraphQLScalarValueFull(kind),
-            };
-        }
-
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static GraphQLEnumValueDefinition CreateGraphQLEnumValueDefinition(IgnoreOptions options)
         {
@@ -621,6 +609,72 @@ public static GraphQLUnionMemberTypes CreateGraphQLUnionMemberTypes(IgnoreOption
             };
         }
 
+        public static GraphQLEnumValue CreateGraphQLEnumValue(IgnoreOptions options)
+        {
+            return options switch
+            {
+                IgnoreOptions.All => new GraphQLEnumValue(),
+                IgnoreOptions.Comments => new GraphQLEnumValueWithLocation(),
+                IgnoreOptions.Locations => new GraphQLEnumValueWithComment(),
+                _ => new GraphQLEnumValueFull(),
+            };
+        }
+
+        public static GraphQLNullValue CreateGraphQLNullValue(IgnoreOptions options)
+        {
+            return options switch
+            {
+                IgnoreOptions.All => new GraphQLNullValue(),
+                IgnoreOptions.Comments => new GraphQLNullValueWithLocation(),
+                IgnoreOptions.Locations => new GraphQLNullValueWithComment(),
+                _ => new GraphQLNullValueFull(),
+            };
+        }
+
+        public static GraphQLBooleanValue CreateGraphQLBooleanValue(IgnoreOptions options)
+        {
+            return options switch
+            {
+                IgnoreOptions.All => new GraphQLBooleanValue(),
+                IgnoreOptions.Comments => new GraphQLBooleanValueWithLocation(),
+                IgnoreOptions.Locations => new GraphQLBooleanValueWithComment(),
+                _ => new GraphQLBooleanValueFull(),
+            };
+        }
+
+        public static GraphQLFloatValue CreateGraphQLFloatValue(IgnoreOptions options)
+        {
+            return options switch
+            {
+                IgnoreOptions.All => new GraphQLFloatValue(),
+                IgnoreOptions.Comments => new GraphQLFloatValueWithLocation(),
+                IgnoreOptions.Locations => new GraphQLFloatValueWithComment(),
+                _ => new GraphQLFloatValueFull(),
+            };
+        }
+
+        public static GraphQLIntValue CreateGraphQLIntValue(IgnoreOptions options)
+        {
+            return options switch
+            {
+                IgnoreOptions.All => new GraphQLIntValue(),
+                IgnoreOptions.Comments => new GraphQLIntValueWithLocation(),
+                IgnoreOptions.Locations => new GraphQLIntValueWithComment(),
+                _ => new GraphQLIntValueFull(),
+            };
+        }
+
+        public static GraphQLStringValue CreateGraphQLStringValue(IgnoreOptions options)
+        {
+            return options switch
+            {
+                IgnoreOptions.All => new GraphQLStringValue(),
+                IgnoreOptions.Comments => new GraphQLStringValueWithLocation(),
+                IgnoreOptions.Locations => new GraphQLStringValueWithComment(),
+                _ => new GraphQLStringValueFull(),
+            };
+        }
+
         #endregion
     }
 }
diff --git a/src/GraphQLParser/ParserContext.Parse.cs b/src/GraphQLParser/ParserContext.Parse.cs
index 8e37d44a..685aa289 100644
--- a/src/GraphQLParser/ParserContext.Parse.cs
+++ b/src/GraphQLParser/ParserContext.Parse.cs
@@ -64,7 +64,7 @@ private GraphQLArgument ParseArgument()
             var arg = NodeHelper.CreateGraphQLArgument(_ignoreOptions);
 
             arg.Comment = GetComment();
-            arg.Name = ParseName();
+            arg.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#Argument");
             Expect(TokenKind.COLON);
             arg.Value = ParseValueLiteral(false);
             arg.Location = GetLocation(start);
@@ -164,13 +164,14 @@ private GraphQLVariablesDefinition ParseVariablesDefinition()
         }
 
         // http://spec.graphql.org/October2021/#BooleanValue
-        private GraphQLValue ParseBooleanValue()
+        // There is no true/false value check, see calling method.
+        private GraphQLBooleanValue ParseBooleanValue()
         {
             IncreaseDepth();
 
             var token = _currentToken;
 
-            var val = NodeHelper.CreateGraphQLScalarValue(_ignoreOptions, ASTNodeKind.BooleanValue);
+            var val = NodeHelper.CreateGraphQLBooleanValue(_ignoreOptions);
 
             val.Comment = GetComment();
             Advance();
@@ -205,9 +206,9 @@ private ASTNode ParseDefinition()
             return Throw_Unexpected_Token();
         }
 
-        private ASTNode Throw_Unexpected_Token()
+        private ASTNode Throw_Unexpected_Token(string? description = null)
         {
-            throw new GraphQLSyntaxErrorException($"Unexpected {_currentToken}", _source, _currentToken.Start);
+            throw new GraphQLSyntaxErrorException($"Unexpected {_currentToken}{description}", _source, _currentToken.Start);
         }
 
         private List<ASTNode> ParseDefinitionsIfNotEOF()
@@ -303,7 +304,7 @@ private GraphQLDirective ParseDirective()
 
             dir.Comment = GetComment();
             Expect(TokenKind.AT);
-            dir.Name = ParseName();
+            dir.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#Directive");
             dir.Arguments = Peek(TokenKind.PAREN_L) ? ParseArguments() : null;
             dir.Location = GetLocation(start);
 
@@ -333,7 +334,7 @@ private GraphQLDirectiveDefinition ParseDirectiveDefinition()
 
             var def = NodeHelper.CreateGraphQLDirectiveDefinition(_ignoreOptions);
 
-            def.Name = ParseName();
+            def.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#DirectiveDefinition");
             def.Arguments = Peek(TokenKind.PAREN_L) ? ParseArgumentsDefinition() : null;
             def.Repeatable = Peek(TokenKind.NAME) && ParseRepeatable();
             ExpectKeyword("on");
@@ -357,7 +358,7 @@ private bool ParseRepeatable()
                 return true;
             }
 
-            Throw_Unexpected_Token();
+            Throw_Unexpected_Token("; did you miss 'repeatable'?");
             return false; // for compiler
         }
 
@@ -426,7 +427,7 @@ private GraphQLEnumTypeDefinition ParseEnumTypeDefinition()
 
             var def = NodeHelper.CreateGraphQLEnumTypeDefinition(_ignoreOptions);
 
-            def.Name = ParseName();
+            def.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#EnumTypeDefinition");
             def.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
             def.Values = Peek(TokenKind.BRACE_L) ? ParseEnumValuesDefinition() : null;
             def.Description = description;
@@ -450,37 +451,48 @@ private GraphQLEnumTypeExtension ParseEnumTypeExtension()
 
             var extension = NodeHelper.CreateGraphQLEnumTypeExtension(_ignoreOptions);
 
-            extension.Name = ParseName();
+            extension.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#EnumTypeExtension");
             extension.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
             extension.Values = Peek(TokenKind.BRACE_L) ? ParseEnumValuesDefinition() : null;
             extension.Comment = comment;
             extension.Location = GetLocation(start);
 
             if (extension.Directives == null && extension.Values == null)
-                return (GraphQLEnumTypeExtension)Throw_Unexpected_Token();
+                return (GraphQLEnumTypeExtension)Throw_Unexpected_Token("; for more information see http://spec.graphql.org/October2021/#EnumTypeExtension");
 
             DecreaseDepth();
             return extension;
         }
 
         // http://spec.graphql.org/October2021/#EnumValue
-        private GraphQLValue ParseEnumValue() // TODO: deal with enum value as ValueNode vs NameNode
+        private GraphQLEnumValue ParseEnumValue()
         {
             IncreaseDepth();
 
-            var token = _currentToken;
+            int start = _currentToken.Start;
 
-            var val = NodeHelper.CreateGraphQLScalarValue(_ignoreOptions, ASTNodeKind.EnumValue);
+            var val = NodeHelper.CreateGraphQLEnumValue(_ignoreOptions);
 
             val.Comment = GetComment();
-            Advance();
-            val.Value = token.Value;
-            val.Location = GetLocation(token.Start);
+            val.Name = ParseEnumName();
+            val.Location = GetLocation(start);
 
             DecreaseDepth();
             return val;
         }
 
+        // Like ParseFragmentName but without special term in grammar.
+        // TODO: https://github.com/graphql/graphql-spec/issues/919
+        private GraphQLName ParseEnumName()
+        {
+            if (_currentToken.Value == "true" || _currentToken.Value == "false" || _currentToken.Value == "null")
+            {
+                Throw_Unexpected_Token("; enum values are represented as unquoted names but not 'true' or 'false' or 'null'.");
+            }
+
+            return ParseName("; for more information see http://spec.graphql.org/October2021/#EnumValue");
+        }
+
         // http://spec.graphql.org/October2021/#EnumValueDefinition
         private GraphQLEnumValueDefinition ParseEnumValueDefinition()
         {
@@ -496,7 +508,8 @@ private GraphQLEnumValueDefinition ParseEnumValueDefinition()
             var def = NodeHelper.CreateGraphQLEnumValueDefinition(_ignoreOptions);
 
             def.Comment = GetComment();
-            def.Name = ParseName();
+            def.EnumValue = ParseEnumValue();
+            def.Name = def.EnumValue.Name; // ATTENTION: should set Name property (inherited from GraphQLTypeDefinition)
             def.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
             def.Description = description;
             def.Location = GetLocation(start);
@@ -520,7 +533,7 @@ private GraphQLFieldDefinition ParseFieldDefinition()
             var def = NodeHelper.CreateGraphQLFieldDefinition(_ignoreOptions);
 
             def.Comment = GetComment();
-            def.Name = ParseName();
+            def.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#FieldDefinition");
             def.Arguments = Peek(TokenKind.PAREN_L) ? ParseArgumentsDefinition() : null;
             Expect(TokenKind.COLON);
             def.Type = ParseType();
@@ -542,7 +555,7 @@ private GraphQLField ParseField()
             int start = _currentToken.Start;
 
             var nameOrAliasComment = GetComment();
-            var nameOrAlias = ParseName();
+            var nameOrAlias = ParseName("; for more information see http://spec.graphql.org/October2021/#Field");
 
             GraphQLName name;
             GraphQLName? alias;
@@ -559,7 +572,7 @@ private GraphQLField ParseField()
                 nameComment = GetComment();
                 aliasComment = nameOrAliasComment;
 
-                name = ParseName();
+                name = ParseName("; for more information see http://spec.graphql.org/October2021/#Field");
                 alias = nameOrAlias; // TODO: should add Alias AST node + check depth
             }
             else
@@ -595,13 +608,13 @@ private GraphQLField ParseField()
         }
 
         // http://spec.graphql.org/October2021/#FloatValue
-        private GraphQLValue ParseFloatValue(/*bool isConstant*/)
+        private GraphQLFloatValue ParseFloatValue(/*bool isConstant*/)
         {
             IncreaseDepth();
 
             var token = _currentToken;
 
-            var val = NodeHelper.CreateGraphQLScalarValue(_ignoreOptions, ASTNodeKind.FloatValue);
+            var val = NodeHelper.CreateGraphQLFloatValue(_ignoreOptions);
 
             val.Comment = GetComment();
             Advance();
@@ -682,10 +695,10 @@ private GraphQLName ParseFragmentName()
         {
             if (_currentToken.Value == "on")
             {
-                Throw_Unexpected_Token();
+                Throw_Unexpected_Token("; fragment name can not be 'on'.");
             }
 
-            return ParseName();
+            return ParseName("; for more information see http://spec.graphql.org/October2021/#FragmentName");
         }
 
         // http://spec.graphql.org/October2021/#ImplementsInterfaces
@@ -734,7 +747,7 @@ private GraphQLInputObjectTypeDefinition ParseInputObjectTypeDefinition()
 
             def.Comment = GetComment();
             ExpectKeyword("input");
-            def.Name = ParseName();
+            def.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#InputObjectTypeDefinition");
             def.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
             def.Fields = Peek(TokenKind.BRACE_L) ? ParseInputFieldsDefinition() : null;
             def.Description = description;
@@ -756,13 +769,13 @@ private GraphQLInputObjectTypeExtension ParseInputObjectTypeExtension()
 
             extension.Comment = GetComment();
             ExpectKeyword("input");
-            extension.Name = ParseName();
+            extension.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#InputObjectTypeExtension");
             extension.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
             extension.Fields = Peek(TokenKind.BRACE_L) ? ParseInputFieldsDefinition() : null;
             extension.Location = GetLocation(start);
 
             if (extension.Directives == null && extension.Fields == null)
-                return (GraphQLInputObjectTypeExtension)Throw_Unexpected_Token();
+                return (GraphQLInputObjectTypeExtension)Throw_Unexpected_Token("; for more information see http://spec.graphql.org/October2021/#InputObjectTypeExtension");
 
             DecreaseDepth();
             return extension;
@@ -783,7 +796,7 @@ private GraphQLInputValueDefinition ParseInputValueDef()
             var def = NodeHelper.CreateGraphQLInputValueDefinition(_ignoreOptions);
 
             def.Comment = GetComment();
-            def.Name = ParseName();
+            def.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#InputValueDefinition");
             Expect(TokenKind.COLON);
             def.Type = ParseType();
             def.DefaultValue = Skip(TokenKind.EQUALS) ? ParseValueLiteral(true) : null;
@@ -796,13 +809,13 @@ private GraphQLInputValueDefinition ParseInputValueDef()
         }
 
         // http://spec.graphql.org/October2021/#IntValue
-        private GraphQLValue ParseIntValue(/*bool isConstant*/)
+        private GraphQLIntValue ParseIntValue(/*bool isConstant*/)
         {
             IncreaseDepth();
 
             var token = _currentToken;
 
-            var val = NodeHelper.CreateGraphQLScalarValue(_ignoreOptions, ASTNodeKind.IntValue);
+            var val = NodeHelper.CreateGraphQLIntValue(_ignoreOptions);
 
             val.Comment = GetComment();
             Advance();
@@ -829,7 +842,7 @@ private GraphQLInterfaceTypeDefinition ParseInterfaceTypeDefinition()
 
             def.Comment = GetComment();
             ExpectKeyword("interface");
-            def.Name = ParseName();
+            def.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#InterfaceTypeDefinition");
             def.Interfaces = _currentToken.Value == "implements" ? ParseImplementsInterfaces() : null;
             def.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
             def.Fields = Peek(TokenKind.BRACE_L) ? ParseFieldsDefinition() : null;
@@ -852,14 +865,14 @@ private GraphQLInterfaceTypeExtension ParseInterfaceTypeExtension()
 
             extension.Comment = GetComment();
             ExpectKeyword("interface");
-            extension.Name = ParseName();
+            extension.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#InterfaceTypeExtension");
             extension.Interfaces = _currentToken.Value == "implements" ? ParseImplementsInterfaces() : null;
             extension.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
             extension.Fields = Peek(TokenKind.BRACE_L) ? ParseFieldsDefinition() : null;
             extension.Location = GetLocation(start);
 
             if (extension.Directives == null && extension.Fields == null && extension.Interfaces == null)
-                return (GraphQLInterfaceTypeExtension)Throw_Unexpected_Token();
+                return (GraphQLInterfaceTypeExtension)Throw_Unexpected_Token("; for more information see http://spec.graphql.org/October2021/#InterfaceTypeExtension");
 
             DecreaseDepth();
             return extension;
@@ -888,7 +901,7 @@ private GraphQLValue ParseListValue(bool isConstant)
         }
 
         // http://spec.graphql.org/October2021/#Name
-        private GraphQLName ParseName()
+        private GraphQLName ParseName(string description)
         {
             IncreaseDepth();
 
@@ -898,7 +911,7 @@ private GraphQLName ParseName()
             var name = NodeHelper.CreateGraphQLName(_ignoreOptions);
 
             name.Comment = GetComment();
-            Expect(TokenKind.NAME);
+            Expect(TokenKind.NAME, description);
             name.Value = value;
             name.Location = GetLocation(start);
 
@@ -983,7 +996,7 @@ private GraphQLNamedType ParseNamedType()
             var named = NodeHelper.CreateGraphQLNamedType(_ignoreOptions);
 
             named.Comment = GetComment();
-            named.Name = ParseName();
+            named.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#NamedType");
             named.Location = GetLocation(start);
 
             DecreaseDepth();
@@ -1032,7 +1045,7 @@ private GraphQLValue ParseNullValue()
 
             var token = _currentToken;
 
-            var val = NodeHelper.CreateGraphQLScalarValue(_ignoreOptions, ASTNodeKind.NullValue);
+            var val = NodeHelper.CreateGraphQLNullValue(_ignoreOptions);
 
             val.Comment = GetComment();
             val.Value = token.Value;
@@ -1053,7 +1066,7 @@ private GraphQLObjectField ParseObjectField(bool isConstant)
             var field = NodeHelper.CreateGraphQLObjectField(_ignoreOptions);
 
             field.Comment = GetComment();
-            field.Name = ParseName();
+            field.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#ObjectField");
             Expect(TokenKind.COLON);
             field.Value = ParseValueLiteral(isConstant);
             field.Location = GetLocation(start);
@@ -1090,7 +1103,7 @@ private GraphQLObjectTypeDefinition ParseObjectTypeDefinition()
 
             def.Comment = GetComment();
             ExpectKeyword("type");
-            def.Name = ParseName();
+            def.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#ObjectTypeDefinition");
             def.Interfaces = _currentToken.Value == "implements" ? ParseImplementsInterfaces() : null;
             def.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
             def.Fields = Peek(TokenKind.BRACE_L) ? ParseFieldsDefinition() : null;
@@ -1113,14 +1126,14 @@ private GraphQLObjectTypeExtension ParseObjectTypeExtension()
 
             extension.Comment = GetComment();
             ExpectKeyword("type");
-            extension.Name = ParseName();
+            extension.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#ObjectTypeExtension");
             extension.Interfaces = _currentToken.Value == "implements" ? ParseImplementsInterfaces() : null;
             extension.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
             extension.Fields = Peek(TokenKind.BRACE_L) ? ParseFieldsDefinition() : null;
             extension.Location = GetLocation(start);
 
             if (extension.Directives == null && extension.Fields == null && extension.Interfaces == null)
-                return (GraphQLObjectTypeExtension)Throw_Unexpected_Token();
+                return (GraphQLObjectTypeExtension)Throw_Unexpected_Token("; for more information see http://spec.graphql.org/October2021/#ObjectTypeExtension");
 
             DecreaseDepth();
             return extension;
@@ -1146,7 +1159,7 @@ private ASTNode ParseOperationDefinition()
             else
             {
                 def.Operation = ParseOperationType();
-                def.Name = Peek(TokenKind.NAME) ? ParseName() : null; // Peek(TokenKind.NAME) because of anonymous query
+                def.Name = Peek(TokenKind.NAME) ? ParseName("; for more information see http://spec.graphql.org/October2021/#OperationDefinition") : null; // Peek(TokenKind.NAME) because of anonymous query
                 def.Variables = Peek(TokenKind.PAREN_L) ? ParseVariablesDefinition() : null;
                 def.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
                 def.SelectionSet = ParseSelectionSet();
@@ -1237,7 +1250,7 @@ private GraphQLScalarTypeDefinition ParseScalarTypeDefinition()
 
             def.Comment = GetComment();
             ExpectKeyword("scalar");
-            def.Name = ParseName();
+            def.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#ScalarTypeDefinition");
             def.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
             def.Description = description;
             def.Location = GetLocation(start);
@@ -1258,12 +1271,12 @@ private GraphQLScalarTypeExtension ParseScalarTypeExtension()
 
             extension.Comment = GetComment();
             ExpectKeyword("scalar");
-            extension.Name = ParseName();
+            extension.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#ScalarTypeExtension");
             extension.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
             extension.Location = GetLocation(start);
 
             if (extension.Directives == null)
-                return (GraphQLScalarTypeExtension)Throw_Unexpected_Token();
+                return (GraphQLScalarTypeExtension)Throw_Unexpected_Token("; for more information see http://spec.graphql.org/October2021/#ScalarTypeExtension");
 
             DecreaseDepth();
             return extension;
@@ -1320,13 +1333,13 @@ private GraphQLSelectionSet ParseSelectionSet()
         }
 
         // http://spec.graphql.org/October2021/#StringValue
-        private GraphQLScalarValue ParseStringValue(/*bool isConstant*/)
+        private GraphQLStringValue ParseStringValue(/*bool isConstant*/)
         {
             IncreaseDepth();
 
             var token = _currentToken;
 
-            var val = NodeHelper.CreateGraphQLScalarValue(_ignoreOptions, ASTNodeKind.StringValue);
+            var val = NodeHelper.CreateGraphQLStringValue(_ignoreOptions);
 
             val.Comment = GetComment();
             Advance();
@@ -1424,7 +1437,7 @@ private GraphQLTypeExtension ParseTypeExtension()
             if (value == "input")
                 return ParseInputObjectTypeExtension();
 
-            return (GraphQLTypeExtension)Throw_Unexpected_Token();
+            return (GraphQLTypeExtension)Throw_Unexpected_Token("; for more information see http://spec.graphql.org/October2021/#TypeExtension");
         }
 
         // http://spec.graphql.org/October2021/#UnionMemberTypes
@@ -1473,7 +1486,7 @@ private GraphQLUnionTypeDefinition ParseUnionTypeDefinition()
 
             def.Comment = GetComment();
             ExpectKeyword("union");
-            def.Name = ParseName();
+            def.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#UnionTypeDefinition");
             def.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
             def.Types = Peek(TokenKind.EQUALS) ? ParseUnionMemberTypes() : null;
             def.Description = description;
@@ -1495,13 +1508,13 @@ private GraphQLUnionTypeExtension ParseUnionTypeExtension()
 
             extension.Comment = GetComment();
             ExpectKeyword("union");
-            extension.Name = ParseName();
+            extension.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#UnionTypeExtension");
             extension.Directives = Peek(TokenKind.AT) ? ParseDirectives() : null;
             extension.Types = Peek(TokenKind.EQUALS) ? ParseUnionMemberTypes() : null;
             extension.Location = GetLocation(start);
 
             if (extension.Directives == null && extension.Types == null)
-                return (GraphQLUnionTypeExtension)Throw_Unexpected_Token();
+                return (GraphQLUnionTypeExtension)Throw_Unexpected_Token("; for more information see http://spec.graphql.org/October2021/#UnionTypeExtension");
 
             DecreaseDepth();
             return extension;
@@ -1533,7 +1546,7 @@ private GraphQLVariable ParseVariable()
 
             variable.Comment = GetComment();
             Expect(TokenKind.DOLLAR);
-            variable.Name = ParseName();
+            variable.Name = ParseName("; for more information see http://spec.graphql.org/October2021/#Variable");
             variable.Location = GetLocation(start);
 
             DecreaseDepth();
diff --git a/src/GraphQLParser/ParserContext.cs b/src/GraphQLParser/ParserContext.cs
index d31faa29..37ee2148 100644
--- a/src/GraphQLParser/ParserContext.cs
+++ b/src/GraphQLParser/ParserContext.cs
@@ -166,7 +166,7 @@ private void Advance(bool fromParseComment = false)
             }
         }
 
-        private void Expect(TokenKind kind)
+        private void Expect(TokenKind kind, string? description = null)
         {
             if (_currentToken.Kind == kind)
             {
@@ -174,13 +174,13 @@ private void Expect(TokenKind kind)
             }
             else
             {
-                Throw_From_Expect(kind);
+                Throw_From_Expect(kind, description);
             }
         }
 
-        private void Throw_From_Expect(TokenKind kind)
+        private void Throw_From_Expect(TokenKind kind, string? description = null)
         {
-            throw new GraphQLSyntaxErrorException($"Expected {Token.GetTokenKindDescription(kind)}, found {_currentToken}", _source, _currentToken.Start);
+            throw new GraphQLSyntaxErrorException($"Expected {Token.GetTokenKindDescription(kind)}, found {_currentToken}{description}", _source, _currentToken.Start);
         }
 
         private void ExpectKeyword(string keyword)
diff --git a/src/GraphQLParser/Visitors/DefaultNodeVisitor.cs b/src/GraphQLParser/Visitors/DefaultNodeVisitor.cs
index 3b0df0c1..07581bb5 100644
--- a/src/GraphQLParser/Visitors/DefaultNodeVisitor.cs
+++ b/src/GraphQLParser/Visitors/DefaultNodeVisitor.cs
@@ -158,33 +158,34 @@ public virtual async ValueTask VisitFragmentDefinition(GraphQLFragmentDefinition
         }
 
         /// <inheritdoc/>
-        public virtual async ValueTask VisitIntValue(GraphQLScalarValue intValue, TContext context)
+        public virtual async ValueTask VisitIntValue(GraphQLIntValue intValue, TContext context)
         {
             await Visit(intValue.Comment, context).ConfigureAwait(false);
         }
 
         /// <inheritdoc/>
-        public virtual async ValueTask VisitFloatValue(GraphQLScalarValue floatValue, TContext context)
+        public virtual async ValueTask VisitFloatValue(GraphQLFloatValue floatValue, TContext context)
         {
             await Visit(floatValue.Comment, context).ConfigureAwait(false);
         }
 
         /// <inheritdoc/>
-        public virtual async ValueTask VisitStringValue(GraphQLScalarValue stringValue, TContext context)
+        public virtual async ValueTask VisitStringValue(GraphQLStringValue stringValue, TContext context)
         {
             await Visit(stringValue.Comment, context).ConfigureAwait(false);
         }
 
         /// <inheritdoc/>
-        public virtual async ValueTask VisitBooleanValue(GraphQLScalarValue booleanValue, TContext context)
+        public virtual async ValueTask VisitBooleanValue(GraphQLBooleanValue booleanValue, TContext context)
         {
             await Visit(booleanValue.Comment, context).ConfigureAwait(false);
         }
 
         /// <inheritdoc/>
-        public virtual async ValueTask VisitEnumValue(GraphQLScalarValue enumValue, TContext context)
+        public virtual async ValueTask VisitEnumValue(GraphQLEnumValue enumValue, TContext context)
         {
             await Visit(enumValue.Comment, context).ConfigureAwait(false);
+            await Visit(enumValue.Name, context).ConfigureAwait(false);
         }
 
         /// <inheritdoc/>
@@ -245,7 +246,7 @@ public virtual async ValueTask VisitNonNullType(GraphQLNonNullType nonNullType,
         }
 
         /// <inheritdoc/>
-        public virtual async ValueTask VisitNullValue(GraphQLScalarValue nullValue, TContext context)
+        public virtual async ValueTask VisitNullValue(GraphQLNullValue nullValue, TContext context)
         {
             await Visit(nullValue.Comment, context).ConfigureAwait(false);
         }
@@ -362,7 +363,7 @@ public virtual async ValueTask VisitEnumValueDefinition(GraphQLEnumValueDefiniti
         {
             await Visit(enumValueDefinition.Comment, context).ConfigureAwait(false);
             await Visit(enumValueDefinition.Description, context).ConfigureAwait(false);
-            await Visit(enumValueDefinition.Name, context).ConfigureAwait(false);
+            await Visit(enumValueDefinition.EnumValue, context).ConfigureAwait(false);
             await Visit(enumValueDefinition.Directives, context).ConfigureAwait(false);
         }
 
@@ -496,16 +497,12 @@ public virtual ValueTask Visit(ASTNode? node, TContext context)
                     GraphQLOperationDefinition operationDefinition => VisitOperationDefinition(operationDefinition, context),
                     GraphQLRootOperationTypeDefinition rootOperationTypeDefinition => VisitRootOperationTypeDefinition(rootOperationTypeDefinition, context),
                     GraphQLScalarTypeDefinition scalarTypeDefinition => VisitScalarTypeDefinition(scalarTypeDefinition, context),
-                    GraphQLScalarValue scalarValue => scalarValue.Kind switch
-                    {
-                        ASTNodeKind.BooleanValue => VisitBooleanValue(scalarValue, context),
-                        ASTNodeKind.EnumValue => VisitEnumValue(scalarValue, context),
-                        ASTNodeKind.FloatValue => VisitFloatValue(scalarValue, context),
-                        ASTNodeKind.IntValue => VisitIntValue(scalarValue, context),
-                        ASTNodeKind.NullValue => VisitNullValue(scalarValue, context),
-                        ASTNodeKind.StringValue => VisitStringValue(scalarValue, context),
-                        _ => throw new NotSupportedException($"Unknown GraphQLScalarValue of kind '{scalarValue.Kind}'."),
-                    },
+                    GraphQLBooleanValue boolValue => VisitBooleanValue(boolValue, context),
+                    GraphQLEnumValue enumValue => VisitEnumValue(enumValue, context),
+                    GraphQLFloatValue floatValue => VisitFloatValue(floatValue, context),
+                    GraphQLIntValue intValue => VisitIntValue(intValue, context),
+                    GraphQLNullValue nullValue => VisitNullValue(nullValue, context),
+                    GraphQLStringValue stringValue => VisitStringValue(stringValue, context),
                     GraphQLSchemaDefinition schemaDefinition => VisitSchemaDefinition(schemaDefinition, context),
                     GraphQLSelectionSet selectionSet => VisitSelectionSet(selectionSet, context),
                     GraphQLScalarTypeExtension scalarEx => VisitScalarTypeExtension(scalarEx, context),
diff --git a/src/GraphQLParser/Visitors/INodeVisitor.cs b/src/GraphQLParser/Visitors/INodeVisitor.cs
index 6aaa357a..6d12e3e5 100644
--- a/src/GraphQLParser/Visitors/INodeVisitor.cs
+++ b/src/GraphQLParser/Visitors/INodeVisitor.cs
@@ -81,29 +81,29 @@ public interface INodeVisitor<TContext>
         ValueTask VisitFragmentDefinition(GraphQLFragmentDefinition fragmentDefinition, TContext context);
 
         /// <summary>
-        /// Visits <see cref="GraphQLScalarValue"/> node.
+        /// Visits <see cref="GraphQLIntValue"/> node.
         /// </summary>
-        ValueTask VisitIntValue(GraphQLScalarValue intValue, TContext context);
+        ValueTask VisitIntValue(GraphQLIntValue intValue, TContext context);
 
         /// <summary>
-        /// Visits <see cref="GraphQLScalarValue"/> node.
+        /// Visits <see cref="GraphQLFloatValue"/> node.
         /// </summary>
-        ValueTask VisitFloatValue(GraphQLScalarValue floatValue, TContext context);
+        ValueTask VisitFloatValue(GraphQLFloatValue floatValue, TContext context);
 
         /// <summary>
-        /// Visits <see cref="GraphQLScalarValue"/> node.
+        /// Visits <see cref="GraphQLStringValue"/> node.
         /// </summary>
-        ValueTask VisitStringValue(GraphQLScalarValue stringValue, TContext context);
+        ValueTask VisitStringValue(GraphQLStringValue stringValue, TContext context);
 
         /// <summary>
-        /// Visits <see cref="GraphQLScalarValue"/> node.
+        /// Visits <see cref="GraphQLBooleanValue"/> node.
         /// </summary>
-        ValueTask VisitBooleanValue(GraphQLScalarValue booleanValue, TContext context);
+        ValueTask VisitBooleanValue(GraphQLBooleanValue booleanValue, TContext context);
 
         /// <summary>
-        /// Visits <see cref="GraphQLScalarValue"/> node.
+        /// Visits <see cref="GraphQLEnumValue"/> node.
         /// </summary>
-        ValueTask VisitEnumValue(GraphQLScalarValue enumValue, TContext context);
+        ValueTask VisitEnumValue(GraphQLEnumValue enumValue, TContext context);
 
         /// <summary>
         /// Visits <see cref="GraphQLListValue"/> node.
@@ -146,9 +146,9 @@ public interface INodeVisitor<TContext>
         ValueTask VisitNonNullType(GraphQLNonNullType nonNullType, TContext context);
 
         /// <summary>
-        /// Visits <see cref="GraphQLScalarValue"/> node.
+        /// Visits <see cref="GraphQLNullValue"/> node.
         /// </summary>
-        ValueTask VisitNullValue(GraphQLScalarValue nullValue, TContext context);
+        ValueTask VisitNullValue(GraphQLNullValue nullValue, TContext context);
 
         /// <summary>
         /// Visits <see cref="GraphQLSchemaDefinition"/> node.
diff --git a/src/GraphQLParser/Visitors/SDLWriter.cs b/src/GraphQLParser/Visitors/SDLWriter.cs
index 027acffb..d8dddc32 100644
--- a/src/GraphQLParser/Visitors/SDLWriter.cs
+++ b/src/GraphQLParser/Visitors/SDLWriter.cs
@@ -359,7 +359,7 @@ public override async ValueTask VisitVariable(GraphQLVariable variable, TContext
         }
 
         /// <inheritdoc/>
-        public override async ValueTask VisitBooleanValue(GraphQLScalarValue booleanValue, TContext context)
+        public override async ValueTask VisitBooleanValue(GraphQLBooleanValue booleanValue, TContext context)
         {
             await Visit(booleanValue.Comment, context).ConfigureAwait(false);
             await context.Write(booleanValue.Value).ConfigureAwait(false);
@@ -750,38 +750,38 @@ public override async ValueTask VisitListValue(GraphQLListValue listValue, TCont
         }
 
         /// <inheritdoc/>
-        public override async ValueTask VisitNullValue(GraphQLScalarValue nullValue, TContext context)
+        public override async ValueTask VisitNullValue(GraphQLNullValue nullValue, TContext context)
         {
             await Visit(nullValue.Comment, context).ConfigureAwait(false);
             await context.Write("null").ConfigureAwait(false);
         }
 
         /// <inheritdoc/>
-        public override async ValueTask VisitStringValue(GraphQLScalarValue stringValue, TContext context)
+        public override async ValueTask VisitStringValue(GraphQLStringValue stringValue, TContext context)
         {
             await Visit(stringValue.Comment, context).ConfigureAwait(false);
             await WriteEncodedString(context, stringValue.Value);
         }
 
         /// <inheritdoc/>
-        public override async ValueTask VisitIntValue(GraphQLScalarValue intValue, TContext context)
+        public override async ValueTask VisitIntValue(GraphQLIntValue intValue, TContext context)
         {
             await Visit(intValue.Comment, context).ConfigureAwait(false);
             await context.Write(intValue.Value).ConfigureAwait(false);
         }
 
         /// <inheritdoc/>
-        public override async ValueTask VisitFloatValue(GraphQLScalarValue floatValue, TContext context)
+        public override async ValueTask VisitFloatValue(GraphQLFloatValue floatValue, TContext context)
         {
             await Visit(floatValue.Comment, context).ConfigureAwait(false);
             await context.Write(floatValue.Value).ConfigureAwait(false);
         }
 
         /// <inheritdoc/>
-        public override async ValueTask VisitEnumValue(GraphQLScalarValue enumValue, TContext context)
+        public override async ValueTask VisitEnumValue(GraphQLEnumValue enumValue, TContext context)
         {
             await Visit(enumValue.Comment, context).ConfigureAwait(false);
-            await context.Write(enumValue.Value).ConfigureAwait(false);
+            await Visit(enumValue.Name, context).ConfigureAwait(false);
         }
 
         /// <inheritdoc/>