diff --git a/internal/checker/nodebuilderimpl.go b/internal/checker/nodebuilderimpl.go
index b1e539d621..2eda08fd60 100644
--- a/internal/checker/nodebuilderimpl.go
+++ b/internal/checker/nodebuilderimpl.go
@@ -2160,7 +2160,15 @@ func (b *NodeBuilderImpl) indexInfoToIndexSignatureDeclarationHelper(indexInfo *
 }
 
 func hasTypeAnnotation(declaration *ast.Declaration) bool {
-	return declaration != nil && declaration.Type() != nil
+	if declaration == nil || declaration.Type() == nil {
+		return false
+	}
+	// Type alias declarations have a .Type() that is their type definition, not a type annotation on a value.
+	// Exclude them so callers don't mistake them for annotated value declarations.
+	if ast.IsTypeAliasDeclaration(declaration) || ast.IsJSTypeAliasDeclaration(declaration) {
+		return false
+	}
+	return true
 }
 
 /**
diff --git a/testdata/baselines/reference/compiler/jsTypedefMergedWithModuleExportProperty.errors.txt b/testdata/baselines/reference/compiler/jsTypedefMergedWithModuleExportProperty.errors.txt
new file mode 100644
index 0000000000..518283e1cb
--- /dev/null
+++ b/testdata/baselines/reference/compiler/jsTypedefMergedWithModuleExportProperty.errors.txt
@@ -0,0 +1,20 @@
+local-lib/ModuleGraphConnection.js(3,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
+local-lib/ModuleGraphConnection.js(4,16): error TS2339: Property 'T' does not exist on type 'typeof ModuleGraphConnection'.
+
+
+==== local-lib/ModuleGraphConnection.js (2 errors) ====
+    /** @typedef {typeof T} T */
+    const T = Symbol();
+    module.exports = class ModuleGraphConnection {};
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
+    module.exports.T = T;
+                   ~
+!!! error TS2339: Property 'T' does not exist on type 'typeof ModuleGraphConnection'.
+    
+==== repro.js (0 errors) ====
+    'use strict';
+    /** @typedef {import('./local-lib/ModuleGraphConnection')} ImportedType */
+    /** @type {ImportedType} */
+    module.exports = class Repro {};
+    
\ No newline at end of file
diff --git a/testdata/baselines/reference/compiler/jsTypedefMergedWithModuleExportProperty.js b/testdata/baselines/reference/compiler/jsTypedefMergedWithModuleExportProperty.js
new file mode 100644
index 0000000000..9708ba8ee6
--- /dev/null
+++ b/testdata/baselines/reference/compiler/jsTypedefMergedWithModuleExportProperty.js
@@ -0,0 +1,48 @@
+//// [tests/cases/compiler/jsTypedefMergedWithModuleExportProperty.ts] ////
+
+//// [ModuleGraphConnection.js]
+/** @typedef {typeof T} T */
+const T = Symbol();
+module.exports = class ModuleGraphConnection {};
+module.exports.T = T;
+
+//// [repro.js]
+'use strict';
+/** @typedef {import('./local-lib/ModuleGraphConnection')} ImportedType */
+/** @type {ImportedType} */
+module.exports = class Repro {};
+
+
+//// [ModuleGraphConnection.js]
+"use strict";
+/** @typedef {typeof T} T */
+const T = Symbol();
+module.exports = class ModuleGraphConnection {
+};
+module.exports.T = T;
+//// [repro.js]
+'use strict';
+/** @typedef {import('./local-lib/ModuleGraphConnection')} ImportedType */
+/** @type {ImportedType} */
+module.exports = class Repro {
+};
+
+
+//// [ModuleGraphConnection.d.ts]
+export = ModuleGraphConnection;
+declare class ModuleGraphConnection {
+}
+declare namespace ModuleGraphConnection {
+    const _exported: typeof T;
+    export { _exported as T };
+}
+export type T = typeof T;
+/** @typedef {typeof T} T */
+declare const T: unique symbol;
+//// [repro.d.ts]
+export = Repro;
+/** @typedef {import('./local-lib/ModuleGraphConnection')} ImportedType */
+/** @type {ImportedType} */
+declare class Repro {
+}
+export type ImportedType = import('./local-lib/ModuleGraphConnection');
diff --git a/testdata/baselines/reference/compiler/jsTypedefMergedWithModuleExportProperty.symbols b/testdata/baselines/reference/compiler/jsTypedefMergedWithModuleExportProperty.symbols
new file mode 100644
index 0000000000..5cd1901280
--- /dev/null
+++ b/testdata/baselines/reference/compiler/jsTypedefMergedWithModuleExportProperty.symbols
@@ -0,0 +1,30 @@
+//// [tests/cases/compiler/jsTypedefMergedWithModuleExportProperty.ts] ////
+
+=== local-lib/ModuleGraphConnection.js ===
+/** @typedef {typeof T} T */
+const T = Symbol();
+>T : Symbol(T, Decl(ModuleGraphConnection.js, 1, 5), Decl(ModuleGraphConnection.js, 0, 4))
+>Symbol : Symbol(Symbol, Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+
+module.exports = class ModuleGraphConnection {};
+>module.exports : Symbol(exports, Decl(ModuleGraphConnection.js, 0, 0))
+>module : Symbol(module, Decl(ModuleGraphConnection.js, 0, 0))
+>exports : Symbol(exports, Decl(ModuleGraphConnection.js, 0, 0))
+>ModuleGraphConnection : Symbol(ModuleGraphConnection, Decl(ModuleGraphConnection.js, 2, 16))
+
+module.exports.T = T;
+>module.exports : Symbol(exports, Decl(ModuleGraphConnection.js, 0, 0))
+>module : Symbol(module, Decl(ModuleGraphConnection.js, 0, 0))
+>exports : Symbol(exports, Decl(ModuleGraphConnection.js, 0, 0))
+>T : Symbol(T, Decl(ModuleGraphConnection.js, 1, 5), Decl(ModuleGraphConnection.js, 0, 4))
+
+=== repro.js ===
+'use strict';
+/** @typedef {import('./local-lib/ModuleGraphConnection')} ImportedType */
+/** @type {ImportedType} */
+module.exports = class Repro {};
+>module.exports : Symbol(exports, Decl(repro.js, 0, 0))
+>module : Symbol(module, Decl(repro.js, 0, 0))
+>exports : Symbol(exports, Decl(repro.js, 0, 0))
+>Repro : Symbol(Repro, Decl(repro.js, 3, 16))
+
diff --git a/testdata/baselines/reference/compiler/jsTypedefMergedWithModuleExportProperty.types b/testdata/baselines/reference/compiler/jsTypedefMergedWithModuleExportProperty.types
new file mode 100644
index 0000000000..eae466ce5f
--- /dev/null
+++ b/testdata/baselines/reference/compiler/jsTypedefMergedWithModuleExportProperty.types
@@ -0,0 +1,40 @@
+//// [tests/cases/compiler/jsTypedefMergedWithModuleExportProperty.ts] ////
+
+=== local-lib/ModuleGraphConnection.js ===
+/** @typedef {typeof T} T */
+const T = Symbol();
+>T : unique symbol
+>Symbol() : unique symbol
+>Symbol : SymbolConstructor
+
+module.exports = class ModuleGraphConnection {};
+>module.exports = class ModuleGraphConnection {} : typeof ModuleGraphConnection
+>module.exports : typeof ModuleGraphConnection
+>module : { exports: typeof ModuleGraphConnection; }
+>exports : typeof ModuleGraphConnection
+>class ModuleGraphConnection {} : typeof ModuleGraphConnection
+>ModuleGraphConnection : typeof ModuleGraphConnection
+
+module.exports.T = T;
+>module.exports.T = T : unique symbol
+>module.exports.T : any
+>module.exports : typeof ModuleGraphConnection
+>module : { exports: typeof ModuleGraphConnection; }
+>exports : typeof ModuleGraphConnection
+>T : any
+>T : unique symbol
+
+=== repro.js ===
+'use strict';
+>'use strict' : "use strict"
+
+/** @typedef {import('./local-lib/ModuleGraphConnection')} ImportedType */
+/** @type {ImportedType} */
+module.exports = class Repro {};
+>module.exports = class Repro {} : typeof Repro
+>module.exports : typeof Repro
+>module : { exports: typeof Repro; }
+>exports : typeof Repro
+>class Repro {} : typeof Repro
+>Repro : typeof Repro
+
diff --git a/testdata/tests/cases/compiler/jsTypedefMergedWithModuleExportProperty.ts b/testdata/tests/cases/compiler/jsTypedefMergedWithModuleExportProperty.ts
new file mode 100644
index 0000000000..2aa7e887f6
--- /dev/null
+++ b/testdata/tests/cases/compiler/jsTypedefMergedWithModuleExportProperty.ts
@@ -0,0 +1,17 @@
+// @allowJs: true
+// @checkJs: true
+// @target: es2015
+// @outDir: ./out
+// @declaration: true
+
+// @filename: local-lib/ModuleGraphConnection.js
+/** @typedef {typeof T} T */
+const T = Symbol();
+module.exports = class ModuleGraphConnection {};
+module.exports.T = T;
+
+// @filename: repro.js
+'use strict';
+/** @typedef {import('./local-lib/ModuleGraphConnection')} ImportedType */
+/** @type {ImportedType} */
+module.exports = class Repro {};