1 files changed, 1 insertions, 1 deletions
diff --git a/runtime.ts b/runtime.ts
index 8929b7112..46538c80f 100644
--- a/runtime.ts
+++ b/runtime.ts
@@ -181,7 +181,7 @@ function resolveModuleName(
 function execute(fileName: string, outputCode: string): void {
   util.assert(outputCode && outputCode.length > 0);
   _global["define"] = makeDefine(fileName);
-  outputCode += "\n//# sourceURL=" + fileName;
+  outputCode += `\n//# sourceURL=${fileName}`;
   globalEval(outputCode);
   _global["define"] = null;
 }