diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index a1f6565ed1f..f792c728227 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -721,7 +721,7 @@ namespace ts {
     /**
      *  List of supported extensions in order of file resolution precedence.
      */
-    export const supportedExtensions = [".ts", ".tsx", ".d.ts"];
+    export const supportedExtensions = [".ts", ".tsx", ".d.ts", ".js"];
 
     const extensionsToRemove = [".d.ts", ".ts", ".js", ".tsx", ".jsx"];
     export function removeFileExtension(path: string): string {