diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index b9e6c0c8f2175..e6a4e229dc07b 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -4536,6 +4536,7 @@ namespace ts {
                     reportLikelyUnsafeImportRequiredError: wrapReportedDiagnostic(tracker.reportLikelyUnsafeImportRequiredError),
                     reportNonlocalAugmentation: wrapReportedDiagnostic(tracker.reportNonlocalAugmentation),
                     reportPrivateInBaseOfClassExpression: wrapReportedDiagnostic(tracker.reportPrivateInBaseOfClassExpression),
+                    reportNonSerializableProperty: wrapReportedDiagnostic(tracker.reportNonSerializableProperty),
                     trackSymbol: oldTrackSymbol && ((...args) => {
                         const result = oldTrackSymbol(...args);
                         if (result) {
@@ -5243,17 +5244,22 @@ namespace ts {
                 const saveEnclosingDeclaration = context.enclosingDeclaration;
                 context.enclosingDeclaration = undefined;
                 if (context.tracker.trackSymbol && getCheckFlags(propertySymbol) & CheckFlags.Late && isLateBoundName(propertySymbol.escapedName)) {
-                    const decl = first(propertySymbol.declarations!);
-                    if (propertySymbol.declarations && hasLateBindableName(decl)) {
-                        if (isBinaryExpression(decl)) {
-                            const name = getNameOfDeclaration(decl);
-                            if (name && isElementAccessExpression(name) && isPropertyAccessEntityNameExpression(name.argumentExpression)) {
-                                trackComputedName(name.argumentExpression, saveEnclosingDeclaration, context);
+                    if (propertySymbol.declarations) {
+                        const decl = first(propertySymbol.declarations);
+                        if (hasLateBindableName(decl)) {
+                            if (isBinaryExpression(decl)) {
+                                const name = getNameOfDeclaration(decl);
+                                if (name && isElementAccessExpression(name) && isPropertyAccessEntityNameExpression(name.argumentExpression)) {
+                                    trackComputedName(name.argumentExpression, saveEnclosingDeclaration, context);
+                                }
+                            }
+                            else {
+                                trackComputedName(decl.name.expression, saveEnclosingDeclaration, context);
                             }
                         }
-                        else {
-                            trackComputedName(decl.name.expression, saveEnclosingDeclaration, context);
-                        }
+                    }
+                    else if (context.tracker?.reportNonSerializableProperty) {
+                        context.tracker.reportNonSerializableProperty(symbolToString(propertySymbol));
                     }
                 }
                 context.enclosingDeclaration = propertySymbol.valueDeclaration || propertySymbol.declarations?.[0] || saveEnclosingDeclaration;
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index dfb655ddff359..46d28a46901c8 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -3801,6 +3801,10 @@
         "category": "Error",
         "code": 4117
     },
+    "The type of this node cannot be serialized because its property '{0}' cannot be serialized.": {
+        "category": "Error",
+        "code": 4118
+    },
 
     "The current host does not support the '{0}' option.": {
         "category": "Error",
diff --git a/src/compiler/transformers/declarations.ts b/src/compiler/transformers/declarations.ts
index 8f41a2ab0d9b7..e76debaa78557 100644
--- a/src/compiler/transformers/declarations.ts
+++ b/src/compiler/transformers/declarations.ts
@@ -77,7 +77,8 @@ namespace ts {
             moduleResolverHost: host,
             trackReferencedAmbientModule,
             trackExternalModuleSymbolOfImportTypeNode,
-            reportNonlocalAugmentation
+            reportNonlocalAugmentation,
+            reportNonSerializableProperty
         };
         let errorNameNode: DeclarationName | undefined;
         let errorFallbackNode: Declaration | undefined;
@@ -228,6 +229,12 @@ namespace ts {
             }
         }
 
+        function reportNonSerializableProperty(propertyName: string) {
+            if (errorNameNode || errorFallbackNode) {
+                context.addDiagnostic(createDiagnosticForNode((errorNameNode || errorFallbackNode)!, Diagnostics.The_type_of_this_node_cannot_be_serialized_because_its_property_0_cannot_be_serialized, propertyName));
+            }
+        }
+
         function transformDeclarationsForJS(sourceFile: SourceFile, bundled?: boolean) {
             const oldDiag = getSymbolAccessibilityDiagnostic;
             getSymbolAccessibilityDiagnostic = (s) => (s.errorNode && canProduceDiagnostics(s.errorNode) ? createGetSymbolAccessibilityDiagnosticForNode(s.errorNode)(s) : ({
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index cea584d3e9802..ec4e85c18766e 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -8238,6 +8238,7 @@ namespace ts {
         trackReferencedAmbientModule?(decl: ModuleDeclaration, symbol: Symbol): void;
         trackExternalModuleSymbolOfImportTypeNode?(symbol: Symbol): void;
         reportNonlocalAugmentation?(containingFile: SourceFile, parentSymbol: Symbol, augmentingSymbol: Symbol): void;
+        reportNonSerializableProperty?(propertyName: string): void;
     }
 
     export interface TextSpan {
diff --git a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.errors.txt b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.errors.txt
new file mode 100644
index 0000000000000..5775ef42eddb1
--- /dev/null
+++ b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.errors.txt
@@ -0,0 +1,11 @@
+tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty.ts(3,1): error TS2741: Property 'length' is missing in type '{ [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; reduce: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; reduceRight: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; find: { <S extends number>(predicate: (this: void, value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [iterator]: () => IterableIterator<number>; [unscopables]: () => { copyWithin: boolean; entries: boolean; fill: boolean; find: boolean; findIndex: boolean; keys: boolean; values: boolean; }; }' but required in type 'number[]'.
+
+
+==== tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty.ts (1 errors) ====
+    declare let tgt2: number[];
+    declare let src2: { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] };
+    tgt2 = src2; // Should error
+    ~~~~
+!!! error TS2741: Property 'length' is missing in type '{ [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; reduce: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; reduceRight: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; find: { <S extends number>(predicate: (this: void, value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [iterator]: () => IterableIterator<number>; [unscopables]: () => { copyWithin: boolean; entries: boolean; fill: boolean; find: boolean; findIndex: boolean; keys: boolean; values: boolean; }; }' but required in type 'number[]'.
+!!! related TS2728 /.ts/lib.es5.d.ts:1224:5: 'length' is declared here.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.js b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.js
new file mode 100644
index 0000000000000..2a819b1dcc32b
--- /dev/null
+++ b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.js
@@ -0,0 +1,8 @@
+//// [mappedTypeWithAsClauseAndLateBoundProperty.ts]
+declare let tgt2: number[];
+declare let src2: { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] };
+tgt2 = src2; // Should error
+
+
+//// [mappedTypeWithAsClauseAndLateBoundProperty.js]
+tgt2 = src2; // Should error
diff --git a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.symbols b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.symbols
new file mode 100644
index 0000000000000..b9656d1ce0b37
--- /dev/null
+++ b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.symbols
@@ -0,0 +1,15 @@
+=== tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty.ts ===
+declare let tgt2: number[];
+>tgt2 : Symbol(tgt2, Decl(mappedTypeWithAsClauseAndLateBoundProperty.ts, 0, 11))
+
+declare let src2: { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] };
+>src2 : Symbol(src2, Decl(mappedTypeWithAsClauseAndLateBoundProperty.ts, 1, 11))
+>K : Symbol(K, Decl(mappedTypeWithAsClauseAndLateBoundProperty.ts, 1, 21))
+>Exclude : Symbol(Exclude, Decl(lib.es5.d.ts, --, --))
+>K : Symbol(K, Decl(mappedTypeWithAsClauseAndLateBoundProperty.ts, 1, 21))
+>K : Symbol(K, Decl(mappedTypeWithAsClauseAndLateBoundProperty.ts, 1, 21))
+
+tgt2 = src2; // Should error
+>tgt2 : Symbol(tgt2, Decl(mappedTypeWithAsClauseAndLateBoundProperty.ts, 0, 11))
+>src2 : Symbol(src2, Decl(mappedTypeWithAsClauseAndLateBoundProperty.ts, 1, 11))
+
diff --git a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.types b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.types
new file mode 100644
index 0000000000000..07618554a7c3c
--- /dev/null
+++ b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.types
@@ -0,0 +1,12 @@
+=== tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty.ts ===
+declare let tgt2: number[];
+>tgt2 : number[]
+
+declare let src2: { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] };
+>src2 : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; reduce: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; reduceRight: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; find: { <S extends number>(predicate: (this: void, value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; [Symbol.unscopables]: () => { copyWithin: boolean; entries: boolean; fill: boolean; find: boolean; findIndex: boolean; keys: boolean; values: boolean; }; }
+
+tgt2 = src2; // Should error
+>tgt2 = src2 : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; reduce: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; reduceRight: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; find: { <S extends number>(predicate: (this: void, value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; [Symbol.unscopables]: () => { copyWithin: boolean; entries: boolean; fill: boolean; find: boolean; findIndex: boolean; keys: boolean; values: boolean; }; }
+>tgt2 : number[]
+>src2 : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; reduce: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; reduceRight: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; find: { <S extends number>(predicate: (this: void, value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; [Symbol.unscopables]: () => { copyWithin: boolean; entries: boolean; fill: boolean; find: boolean; findIndex: boolean; keys: boolean; values: boolean; }; }
+
diff --git a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.errors.txt b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.errors.txt
new file mode 100644
index 0000000000000..087365b20981f
--- /dev/null
+++ b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.errors.txt
@@ -0,0 +1,11 @@
+tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty2.ts(1,14): error TS4118: The type of this node cannot be serialized because its property '[iterator]' cannot be serialized.
+tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty2.ts(1,14): error TS4118: The type of this node cannot be serialized because its property '[unscopables]' cannot be serialized.
+
+
+==== tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty2.ts (2 errors) ====
+    export const thing = (null as any as { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] });
+                 ~~~~~
+!!! error TS4118: The type of this node cannot be serialized because its property '[iterator]' cannot be serialized.
+                 ~~~~~
+!!! error TS4118: The type of this node cannot be serialized because its property '[unscopables]' cannot be serialized.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.js b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.js
new file mode 100644
index 0000000000000..82ced9d506184
--- /dev/null
+++ b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.js
@@ -0,0 +1,6 @@
+//// [mappedTypeWithAsClauseAndLateBoundProperty2.ts]
+export const thing = (null as any as { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] });
+
+
+//// [mappedTypeWithAsClauseAndLateBoundProperty2.js]
+export const thing = null;
diff --git a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.symbols b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.symbols
new file mode 100644
index 0000000000000..27d776a4a0e47
--- /dev/null
+++ b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.symbols
@@ -0,0 +1,8 @@
+=== tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty2.ts ===
+export const thing = (null as any as { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] });
+>thing : Symbol(thing, Decl(mappedTypeWithAsClauseAndLateBoundProperty2.ts, 0, 12))
+>K : Symbol(K, Decl(mappedTypeWithAsClauseAndLateBoundProperty2.ts, 0, 40))
+>Exclude : Symbol(Exclude, Decl(lib.es5.d.ts, --, --))
+>K : Symbol(K, Decl(mappedTypeWithAsClauseAndLateBoundProperty2.ts, 0, 40))
+>K : Symbol(K, Decl(mappedTypeWithAsClauseAndLateBoundProperty2.ts, 0, 40))
+
diff --git a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.types b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.types
new file mode 100644
index 0000000000000..20d056505123f
--- /dev/null
+++ b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.types
@@ -0,0 +1,8 @@
+=== tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty2.ts ===
+export const thing = (null as any as { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] });
+>thing : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; reduce: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; reduceRight: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; find: { <S extends number>(predicate: (this: void, value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; [Symbol.unscopables]: () => { copyWithin: boolean; entries: boolean; fill: boolean; find: boolean; findIndex: boolean; keys: boolean; values: boolean; }; }
+>(null as any as { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] }) : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; reduce: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; reduceRight: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; find: { <S extends number>(predicate: (this: void, value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; [Symbol.unscopables]: () => { copyWithin: boolean; entries: boolean; fill: boolean; find: boolean; findIndex: boolean; keys: boolean; values: boolean; }; }
+>null as any as { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] } : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; reduce: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; reduceRight: { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }; find: { <S extends number>(predicate: (this: void, value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; [Symbol.unscopables]: () => { copyWithin: boolean; entries: boolean; fill: boolean; find: boolean; findIndex: boolean; keys: boolean; values: boolean; }; }
+>null as any : any
+>null : null
+
diff --git a/tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty.ts b/tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty.ts
new file mode 100644
index 0000000000000..5aea06b8b5adf
--- /dev/null
+++ b/tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty.ts
@@ -0,0 +1,4 @@
+// @target: ES2020
+declare let tgt2: number[];
+declare let src2: { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] };
+tgt2 = src2; // Should error
diff --git a/tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty2.ts b/tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty2.ts
new file mode 100644
index 0000000000000..1cb22a7305783
--- /dev/null
+++ b/tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty2.ts
@@ -0,0 +1,3 @@
+// @target: ES2020
+// @declaration: true
+export const thing = (null as any as { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] });