diff --git a/lib/graphql/interface_type.rb b/lib/graphql/interface_type.rb
index bdf5449ff2..bf82f678eb 100644
--- a/lib/graphql/interface_type.rb
+++ b/lib/graphql/interface_type.rb
@@ -23,4 +23,14 @@ def kind
   def possible_types
     @possible_types ||= []
   end
+
+  # @return [GraphQL::Field] The defined field for `field_name`
+  def get_field(field_name)
+    fields[field_name]
+  end
+
+  # @return [Array<GraphQL::Field>] All fields on this type
+  def all_fields
+    fields.values
+  end
 end
diff --git a/lib/graphql/introspection/fields_field.rb b/lib/graphql/introspection/fields_field.rb
index e9fadc319d..779b0adaa8 100644
--- a/lib/graphql/introspection/fields_field.rb
+++ b/lib/graphql/introspection/fields_field.rb
@@ -4,10 +4,10 @@
   argument :includeDeprecated, GraphQL::BOOLEAN_TYPE, default_value: false
   resolve -> (object, arguments, context) {
     return nil if !object.kind.fields?
-    fields = object.fields.values
+    fields = object.all_fields
     if !arguments["includeDeprecated"]
       fields = fields.select {|f| !f.deprecation_reason }
     end
-    fields
+    fields.sort_by { |f| f.name }
   }
 end
diff --git a/lib/graphql/object_type.rb b/lib/graphql/object_type.rb
index c46906277a..2df09d2a47 100644
--- a/lib/graphql/object_type.rb
+++ b/lib/graphql/object_type.rb
@@ -42,4 +42,23 @@ def interfaces=(new_interfaces)
   def kind
     GraphQL::TypeKinds::OBJECT
   end
+
+  # @return [GraphQL::Field] The field definition for `field_name` (may be inherited from interfaces)
+  def get_field(field_name)
+    fields[field_name] || interface_fields[field_name]
+  end
+
+  # @return [Array<GraphQL::Field>] All fields, including ones inherited from interfaces
+  def all_fields
+    interface_fields.merge(self.fields).values
+  end
+
+  private
+
+  # Create a {name => defn} hash for fields inherited from interfaces
+  def interface_fields
+    interfaces.reduce({}) do |memo, iface|
+      memo.merge!(iface.fields)
+    end
+  end
 end
diff --git a/lib/graphql/schema.rb b/lib/graphql/schema.rb
index 380adaff00..642578702b 100644
--- a/lib/graphql/schema.rb
+++ b/lib/graphql/schema.rb
@@ -49,7 +49,7 @@ def execute(*args)
   # Resolve field named `field_name` for type `parent_type`.
   # Handles dynamic fields `__typename`, `__type` and `__schema`, too
   def get_field(parent_type, field_name)
-    defined_field = parent_type.fields[field_name]
+    defined_field = parent_type.get_field(field_name)
     if defined_field
       defined_field
     elsif field_name == "__typename"
diff --git a/lib/graphql/schema/printer.rb b/lib/graphql/schema/printer.rb
index 689bd870b9..a7898d0943 100644
--- a/lib/graphql/schema/printer.rb
+++ b/lib/graphql/schema/printer.rb
@@ -48,7 +48,7 @@ def print_type(type)
     module TypeKindPrinters
       module FieldPrinter
         def print_fields(type)
-          type.fields.values.map{ |field| "  #{field.name}#{print_args(field)}: #{field.type}" }.join("\n")
+          type.all_fields.map{ |field| "  #{field.name}#{print_args(field)}: #{field.type}" }.join("\n")
         end
 
         def print_args(field)
diff --git a/lib/graphql/schema/type_reducer.rb b/lib/graphql/schema/type_reducer.rb
index 687d8a07c3..dd2b89a081 100644
--- a/lib/graphql/schema/type_reducer.rb
+++ b/lib/graphql/schema/type_reducer.rb
@@ -30,7 +30,7 @@ def self.find_all(types)
   def find_types(type, type_hash)
     type_hash[type.name] = type
     if type.kind.fields?
-      type.fields.each do |name, field|
+      type.all_fields.each do |field|
         reduce_type(field.type, type_hash)
         field.arguments.each do |name, argument|
           reduce_type(argument.type, type_hash)
diff --git a/lib/graphql/static_validation/rules/fields_are_defined_on_type.rb b/lib/graphql/static_validation/rules/fields_are_defined_on_type.rb
index ade9db7ec2..e7a7b890cd 100644
--- a/lib/graphql/static_validation/rules/fields_are_defined_on_type.rb
+++ b/lib/graphql/static_validation/rules/fields_are_defined_on_type.rb
@@ -19,7 +19,7 @@ def validate_field(errors, ast_field, parent_type, parent)
       return GraphQL::Language::Visitor::SKIP
     end
 
-    field =  parent_type.fields[ast_field.name]
+    field =  parent_type.get_field(ast_field.name)
     if field.nil?
       errors << message("Field '#{ast_field.name}' doesn't exist on type '#{parent_type.name}'", parent)
       return GraphQL::Language::Visitor::SKIP
diff --git a/readme.md b/readme.md
index 6828334727..04e8c9a4d3 100644
--- a/readme.md
+++ b/readme.md
@@ -140,6 +140,7 @@ https://medium.com/@gauravtiwari/graphql-and-relay-on-rails-first-relay-powered-
 - Add a custom dump for Relay (it expects default value strings to be double-quoted)
 - Make variable validation provide a specific, useful message
 - Add docs for shared behaviors & DRY code
+- Optimize the pure-Ruby parser (hand-write, RACC?!)
 - Big ideas:
   - Revamp the fixture Schema to be more useful (better names, more extensible)
   - __Subscriptions__
diff --git a/spec/graphql/introspection/schema_type_spec.rb b/spec/graphql/introspection/schema_type_spec.rb
index 7c9a6c4d03..99b7cf238d 100644
--- a/spec/graphql/introspection/schema_type_spec.rb
+++ b/spec/graphql/introspection/schema_type_spec.rb
@@ -19,15 +19,15 @@
         "queryType"=>{
           "fields"=>[
             {"name"=>"cheese"},
-            {"name"=>"milk"},
-            {"name"=>"dairy"},
-            {"name"=>"fromSource"},
-            {"name"=>"favoriteEdible"},
             {"name"=>"cow"},
-            {"name"=>"searchDairy"},
+            {"name"=>"dairy"},
             {"name"=>"error"},
             {"name"=>"executionError"},
-            {"name"=>"maybeNull"}
+            {"name"=>"favoriteEdible"},
+            {"name"=>"fromSource"},
+            {"name"=>"maybeNull"},
+            {"name"=>"milk"},
+            {"name"=>"searchDairy"},
           ]
         },
         "mutationType"=> {
diff --git a/spec/graphql/introspection/type_type_spec.rb b/spec/graphql/introspection/type_type_spec.rb
index 71b857d6d5..459e417ec5 100644
--- a/spec/graphql/introspection/type_type_spec.rb
+++ b/spec/graphql/introspection/type_type_spec.rb
@@ -12,11 +12,11 @@
   |}
   let(:result) { DummySchema.execute(query_string, context: {}, variables: {"cheeseId" => 2}) }
   let(:cheese_fields) {[
-    {"name"=>"id",          "isDeprecated" => false, "type" => { "name" => "Non-Null", "ofType" => { "name" => "Int"}}},
     {"name"=>"flavor",      "isDeprecated" => false, "type" => { "name" => "Non-Null", "ofType" => { "name" => "String"}}},
+    {"name"=>"id",          "isDeprecated" => false, "type" => { "name" => "Non-Null", "ofType" => { "name" => "Int"}}},
     {"name"=>"origin",      "isDeprecated" => false, "type" => { "name" => "Non-Null", "ofType" => { "name" => "String"}}},
-    {"name"=>"source",      "isDeprecated" => false, "type" => { "name" => "Non-Null", "ofType" => { "name" => "DairyAnimal"}}},
     {"name"=>"similarCheese", "isDeprecated"=>false, "type"=>{"name"=>"Cheese", "ofType"=>nil}},
+    {"name"=>"source",      "isDeprecated" => false, "type" => { "name" => "Non-Null", "ofType" => { "name" => "DairyAnimal"}}},
   ]}
 
   let(:dairy_animals) {[
@@ -37,11 +37,11 @@
           {"name"=>"AnimalProduct"}
         ],
         "fields"=>[
-          {"type"=>{"name"=>"Non-Null", "ofType"=>{"name"=>"ID"}}},
-          {"type"=>{"name"=>"DairyAnimal", "ofType"=>nil}},
-          {"type"=>{"name"=>"Non-Null", "ofType"=>{"name"=>"String"}}},
           {"type"=>{"name"=>"Non-Null", "ofType"=>{"name"=>"Float"}}},
           {"type"=>{"name"=>"List", "ofType"=>{"name"=>"String"}}},
+          {"type"=>{"name"=>"Non-Null", "ofType"=>{"name"=>"ID"}}},
+          {"type"=>{"name"=>"Non-Null", "ofType"=>{"name"=>"String"}}},
+          {"type"=>{"name"=>"DairyAnimal", "ofType"=>nil}},
         ]
       },
       "dairyAnimal"=>{
@@ -75,7 +75,7 @@
     |}
     let(:deprecated_fields) { {"name"=>"fatContent", "isDeprecated"=>true, "type"=>{"name"=>"Non-Null", "ofType"=>{"name"=>"Float"}}} }
     it 'can expose deprecated fields' do
-      new_cheese_fields = cheese_fields + [deprecated_fields]
+      new_cheese_fields = [deprecated_fields] + cheese_fields
       expected = { "data" => {
         "cheeseType" => {
           "name"=> "Cheese",
diff --git a/spec/graphql/object_type_spec.rb b/spec/graphql/object_type_spec.rb
index b1d388c18b..1f7dd0c154 100644
--- a/spec/graphql/object_type_spec.rb
+++ b/spec/graphql/object_type_spec.rb
@@ -18,18 +18,25 @@
     assert_equal([EdibleInterface, AnimalProductInterface], type.interfaces)
   end
 
-  describe '.fields ' do
+  describe '#get_field ' do
     it 'exposes fields' do
-      field = type.fields["id"]
+      field = type.get_field("id")
       assert_equal(GraphQL::TypeKinds::NON_NULL, field.type.kind)
       assert_equal(GraphQL::TypeKinds::SCALAR, field.type.of_type.kind)
     end
 
     it 'exposes defined field property' do
-      field_without_prop = CheeseType.fields['flavor']
-      field_with_prop = CheeseType.fields['fatContent']
+      field_without_prop = CheeseType.get_field('flavor')
+      field_with_prop = CheeseType.get_field('fatContent')
       assert_equal(field_without_prop.property, nil)
       assert_equal(field_with_prop.property, :fat_content)
     end
+
+    it "looks up from interfaces" do
+      field_from_self = CheeseType.get_field('fatContent')
+      field_from_iface = MilkType.get_field('fatContent')
+      assert_equal(field_from_self.property, :fat_content)
+      assert_equal(field_from_iface.property, nil)
+    end
   end
 end
diff --git a/spec/graphql/schema/type_reducer_spec.rb b/spec/graphql/schema/type_reducer_spec.rb
index ce71ab57c7..7c02bd7c38 100644
--- a/spec/graphql/schema/type_reducer_spec.rb
+++ b/spec/graphql/schema/type_reducer_spec.rb
@@ -5,10 +5,10 @@
     reducer = GraphQL::Schema::TypeReducer.new(CheeseType, {})
     expected = {
       "Cheese" => CheeseType,
-      "Int" => GraphQL::INT_TYPE,
+      "Float" => GraphQL::FLOAT_TYPE,
       "String" => GraphQL::STRING_TYPE,
       "DairyAnimal" => DairyAnimalEnum,
-      "Float" => GraphQL::FLOAT_TYPE,
+      "Int" => GraphQL::INT_TYPE,
       "Edible" => EdibleInterface,
       "Milk" => MilkType,
       "ID" => GraphQL::ID_TYPE,
diff --git a/spec/support/dairy_app.rb b/spec/support/dairy_app.rb
index f4e964e586..8d2a265d29 100644
--- a/spec/support/dairy_app.rb
+++ b/spec/support/dairy_app.rb
@@ -5,7 +5,7 @@ class NoSuchDairyError < StandardError; end
 EdibleInterface = GraphQL::InterfaceType.define do
   name "Edible"
   description "Something you can eat, yum"
-  field :fatContent, !types.Float, "Percentage which is fat", property: :bogus_property
+  field :fatContent, !types.Float, "Percentage which is fat"
   field :origin, !types.String, "Place the edible comes from"
 end
 
@@ -65,7 +65,6 @@ class NoSuchDairyError < StandardError; end
   field :id, !types.ID
   field :source, DairyAnimalEnum, "Animal which produced this milk"
   field :origin, !types.String, "Place the milk comes from"
-  field :fatContent, !types.Float, "Percentage which is milkfat"
   field :flavors, types[types.String], "Chocolate, Strawberry, etc" do
     argument :limit, types.Int
     resolve -> (milk, args, ctx) {