diff --git a/src/compiler/transformers/ts.ts b/src/compiler/transformers/ts.ts
index 4712be940fe..ebf5e662517 100644
--- a/src/compiler/transformers/ts.ts
+++ b/src/compiler/transformers/ts.ts
@@ -1969,7 +1969,16 @@ namespace ts {
          * @param node The type reference node.
          */
         function serializeTypeReferenceNode(node: TypeReferenceNode): SerializedTypeNode {
-            const kind = resolver.getTypeReferenceSerializationKind(node.typeName, currentScope);
+            // node might be a reference to type variable, which can be scoped to a class declaration, in addition to the regular
+            // TypeScript scopes. Walk up the AST to find the next class and use that as the lookup scope.
+            let scope: Node = node;
+            while (scope.parent && scope !== currentScope) {
+                scope = scope.parent;
+                if (isClassDeclaration(scope)) {
+                    break;
+                }
+            }
+            const kind = resolver.getTypeReferenceSerializationKind(node.typeName, scope);
             switch (kind) {
                 case TypeReferenceSerializationKind.Unknown:
                     const serialized = serializeEntityNameAsExpression(node.typeName, /*useFallback*/ true);
diff --git a/tests/baselines/reference/decoratorMetadataGenericTypeVariable.errors.txt b/tests/baselines/reference/decoratorMetadataGenericTypeVariable.errors.txt
new file mode 100644
index 00000000000..77258e37a9f
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataGenericTypeVariable.errors.txt
@@ -0,0 +1,11 @@
+tests/cases/compiler/decoratorMetadataGenericTypeVariable.ts(2,4): error TS2304: Cannot find name 'Decorate'.
+
+
+==== tests/cases/compiler/decoratorMetadataGenericTypeVariable.ts (1 errors) ====
+    export class C<TypeVariable> {
+      @Decorate
+       ~~~~~~~~
+!!! error TS2304: Cannot find name 'Decorate'.
+      member: TypeVariable;
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/decoratorMetadataGenericTypeVariable.js b/tests/baselines/reference/decoratorMetadataGenericTypeVariable.js
new file mode 100644
index 00000000000..08d4f4a856f
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataGenericTypeVariable.js
@@ -0,0 +1,29 @@
+//// [decoratorMetadataGenericTypeVariable.ts]
+export class C<TypeVariable> {
+  @Decorate
+  member: TypeVariable;
+}
+
+
+//// [decoratorMetadataGenericTypeVariable.js]
+"use strict";
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var __metadata = (this && this.__metadata) || function (k, v) {
+    if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
+};
+exports.__esModule = true;
+var C = /** @class */ (function () {
+    function C() {
+    }
+    __decorate([
+        Decorate,
+        __metadata("design:type", Object)
+    ], C.prototype, "member");
+    return C;
+}());
+exports.C = C;
diff --git a/tests/baselines/reference/decoratorMetadataGenericTypeVariable.symbols b/tests/baselines/reference/decoratorMetadataGenericTypeVariable.symbols
new file mode 100644
index 00000000000..d01f6d5523a
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataGenericTypeVariable.symbols
@@ -0,0 +1,11 @@
+=== tests/cases/compiler/decoratorMetadataGenericTypeVariable.ts ===
+export class C<TypeVariable> {
+>C : Symbol(C, Decl(decoratorMetadataGenericTypeVariable.ts, 0, 0))
+>TypeVariable : Symbol(TypeVariable, Decl(decoratorMetadataGenericTypeVariable.ts, 0, 15))
+
+  @Decorate
+  member: TypeVariable;
+>member : Symbol(C.member, Decl(decoratorMetadataGenericTypeVariable.ts, 0, 30))
+>TypeVariable : Symbol(TypeVariable, Decl(decoratorMetadataGenericTypeVariable.ts, 0, 15))
+}
+
diff --git a/tests/baselines/reference/decoratorMetadataGenericTypeVariable.types b/tests/baselines/reference/decoratorMetadataGenericTypeVariable.types
new file mode 100644
index 00000000000..8d4965f9942
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataGenericTypeVariable.types
@@ -0,0 +1,13 @@
+=== tests/cases/compiler/decoratorMetadataGenericTypeVariable.ts ===
+export class C<TypeVariable> {
+>C : C<TypeVariable>
+>TypeVariable : TypeVariable
+
+  @Decorate
+>Decorate : any
+
+  member: TypeVariable;
+>member : TypeVariable
+>TypeVariable : TypeVariable
+}
+
diff --git a/tests/baselines/reference/decoratorMetadataGenericTypeVariableDefault.errors.txt b/tests/baselines/reference/decoratorMetadataGenericTypeVariableDefault.errors.txt
new file mode 100644
index 00000000000..324aafbc6ed
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataGenericTypeVariableDefault.errors.txt
@@ -0,0 +1,11 @@
+tests/cases/compiler/decoratorMetadataGenericTypeVariableDefault.ts(2,4): error TS2304: Cannot find name 'Decorate'.
+
+
+==== tests/cases/compiler/decoratorMetadataGenericTypeVariableDefault.ts (1 errors) ====
+    export class C<TypeVariable = string> {
+      @Decorate
+       ~~~~~~~~
+!!! error TS2304: Cannot find name 'Decorate'.
+      member: TypeVariable;
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/decoratorMetadataGenericTypeVariableDefault.js b/tests/baselines/reference/decoratorMetadataGenericTypeVariableDefault.js
new file mode 100644
index 00000000000..9c3c309d503
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataGenericTypeVariableDefault.js
@@ -0,0 +1,29 @@
+//// [decoratorMetadataGenericTypeVariableDefault.ts]
+export class C<TypeVariable = string> {
+  @Decorate
+  member: TypeVariable;
+}
+
+
+//// [decoratorMetadataGenericTypeVariableDefault.js]
+"use strict";
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var __metadata = (this && this.__metadata) || function (k, v) {
+    if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
+};
+exports.__esModule = true;
+var C = /** @class */ (function () {
+    function C() {
+    }
+    __decorate([
+        Decorate,
+        __metadata("design:type", Object)
+    ], C.prototype, "member");
+    return C;
+}());
+exports.C = C;
diff --git a/tests/baselines/reference/decoratorMetadataGenericTypeVariableDefault.symbols b/tests/baselines/reference/decoratorMetadataGenericTypeVariableDefault.symbols
new file mode 100644
index 00000000000..178fc2efeb0
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataGenericTypeVariableDefault.symbols
@@ -0,0 +1,11 @@
+=== tests/cases/compiler/decoratorMetadataGenericTypeVariableDefault.ts ===
+export class C<TypeVariable = string> {
+>C : Symbol(C, Decl(decoratorMetadataGenericTypeVariableDefault.ts, 0, 0))
+>TypeVariable : Symbol(TypeVariable, Decl(decoratorMetadataGenericTypeVariableDefault.ts, 0, 15))
+
+  @Decorate
+  member: TypeVariable;
+>member : Symbol(C.member, Decl(decoratorMetadataGenericTypeVariableDefault.ts, 0, 39))
+>TypeVariable : Symbol(TypeVariable, Decl(decoratorMetadataGenericTypeVariableDefault.ts, 0, 15))
+}
+
diff --git a/tests/baselines/reference/decoratorMetadataGenericTypeVariableDefault.types b/tests/baselines/reference/decoratorMetadataGenericTypeVariableDefault.types
new file mode 100644
index 00000000000..1bbe1b3fb70
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataGenericTypeVariableDefault.types
@@ -0,0 +1,13 @@
+=== tests/cases/compiler/decoratorMetadataGenericTypeVariableDefault.ts ===
+export class C<TypeVariable = string> {
+>C : C<TypeVariable>
+>TypeVariable : TypeVariable
+
+  @Decorate
+>Decorate : any
+
+  member: TypeVariable;
+>member : TypeVariable
+>TypeVariable : TypeVariable
+}
+
diff --git a/tests/baselines/reference/decoratorMetadataGenericTypeVariableInScope.errors.txt b/tests/baselines/reference/decoratorMetadataGenericTypeVariableInScope.errors.txt
new file mode 100644
index 00000000000..9a5016af1fa
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataGenericTypeVariableInScope.errors.txt
@@ -0,0 +1,14 @@
+tests/cases/compiler/decoratorMetadataGenericTypeVariableInScope.ts(5,4): error TS2304: Cannot find name 'Decorate'.
+
+
+==== tests/cases/compiler/decoratorMetadataGenericTypeVariableInScope.ts (1 errors) ====
+    // Unused, but could collide with the named type argument below.
+    class TypeVariable {}
+    
+    export class C<TypeVariable> {
+      @Decorate
+       ~~~~~~~~
+!!! error TS2304: Cannot find name 'Decorate'.
+      member: TypeVariable;
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/decoratorMetadataGenericTypeVariableInScope.js b/tests/baselines/reference/decoratorMetadataGenericTypeVariableInScope.js
new file mode 100644
index 00000000000..aa5dd1db522
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataGenericTypeVariableInScope.js
@@ -0,0 +1,38 @@
+//// [decoratorMetadataGenericTypeVariableInScope.ts]
+// Unused, but could collide with the named type argument below.
+class TypeVariable {}
+
+export class C<TypeVariable> {
+  @Decorate
+  member: TypeVariable;
+}
+
+
+//// [decoratorMetadataGenericTypeVariableInScope.js]
+"use strict";
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var __metadata = (this && this.__metadata) || function (k, v) {
+    if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
+};
+exports.__esModule = true;
+// Unused, but could collide with the named type argument below.
+var TypeVariable = /** @class */ (function () {
+    function TypeVariable() {
+    }
+    return TypeVariable;
+}());
+var C = /** @class */ (function () {
+    function C() {
+    }
+    __decorate([
+        Decorate,
+        __metadata("design:type", Object)
+    ], C.prototype, "member");
+    return C;
+}());
+exports.C = C;
diff --git a/tests/baselines/reference/decoratorMetadataGenericTypeVariableInScope.symbols b/tests/baselines/reference/decoratorMetadataGenericTypeVariableInScope.symbols
new file mode 100644
index 00000000000..3f415fb440b
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataGenericTypeVariableInScope.symbols
@@ -0,0 +1,15 @@
+=== tests/cases/compiler/decoratorMetadataGenericTypeVariableInScope.ts ===
+// Unused, but could collide with the named type argument below.
+class TypeVariable {}
+>TypeVariable : Symbol(TypeVariable, Decl(decoratorMetadataGenericTypeVariableInScope.ts, 0, 0))
+
+export class C<TypeVariable> {
+>C : Symbol(C, Decl(decoratorMetadataGenericTypeVariableInScope.ts, 1, 21))
+>TypeVariable : Symbol(TypeVariable, Decl(decoratorMetadataGenericTypeVariableInScope.ts, 3, 15))
+
+  @Decorate
+  member: TypeVariable;
+>member : Symbol(C.member, Decl(decoratorMetadataGenericTypeVariableInScope.ts, 3, 30))
+>TypeVariable : Symbol(TypeVariable, Decl(decoratorMetadataGenericTypeVariableInScope.ts, 3, 15))
+}
+
diff --git a/tests/baselines/reference/decoratorMetadataGenericTypeVariableInScope.types b/tests/baselines/reference/decoratorMetadataGenericTypeVariableInScope.types
new file mode 100644
index 00000000000..b81214cd170
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataGenericTypeVariableInScope.types
@@ -0,0 +1,17 @@
+=== tests/cases/compiler/decoratorMetadataGenericTypeVariableInScope.ts ===
+// Unused, but could collide with the named type argument below.
+class TypeVariable {}
+>TypeVariable : TypeVariable
+
+export class C<TypeVariable> {
+>C : C<TypeVariable>
+>TypeVariable : TypeVariable
+
+  @Decorate
+>Decorate : any
+
+  member: TypeVariable;
+>member : TypeVariable
+>TypeVariable : TypeVariable
+}
+
diff --git a/tests/cases/compiler/decoratorMetadataGenericTypeVariable.ts b/tests/cases/compiler/decoratorMetadataGenericTypeVariable.ts
new file mode 100644
index 00000000000..99e603d490e
--- /dev/null
+++ b/tests/cases/compiler/decoratorMetadataGenericTypeVariable.ts
@@ -0,0 +1,7 @@
+// @experimentalDecorators: true
+// @emitDecoratorMetadata: true
+
+export class C<TypeVariable> {
+  @Decorate
+  member: TypeVariable;
+}
diff --git a/tests/cases/compiler/decoratorMetadataGenericTypeVariableDefault.ts b/tests/cases/compiler/decoratorMetadataGenericTypeVariableDefault.ts
new file mode 100644
index 00000000000..efb7be349c4
--- /dev/null
+++ b/tests/cases/compiler/decoratorMetadataGenericTypeVariableDefault.ts
@@ -0,0 +1,7 @@
+// @experimentalDecorators: true
+// @emitDecoratorMetadata: true
+
+export class C<TypeVariable = string> {
+  @Decorate
+  member: TypeVariable;
+}
diff --git a/tests/cases/compiler/decoratorMetadataGenericTypeVariableInScope.ts b/tests/cases/compiler/decoratorMetadataGenericTypeVariableInScope.ts
new file mode 100644
index 00000000000..fac33aa5e24
--- /dev/null
+++ b/tests/cases/compiler/decoratorMetadataGenericTypeVariableInScope.ts
@@ -0,0 +1,10 @@
+// @experimentalDecorators: true
+// @emitDecoratorMetadata: true
+
+// Unused, but could collide with the named type argument below.
+class TypeVariable {}
+
+export class C<TypeVariable> {
+  @Decorate
+  member: TypeVariable;
+}