diff --git a/local-cli/bundle/buildBundle.js b/local-cli/bundle/buildBundle.js
index 8c989e52145..2693e4917b5 100644
--- a/local-cli/bundle/buildBundle.js
+++ b/local-cli/bundle/buildBundle.js
@@ -28,7 +28,7 @@ function buildBundle(args, config, output = outputBundle, packagerInstance) {
 
   const requestOpts = {
     entryFile: args.entryFile,
-    sourceMapUrl: path.basename(args.sourcemapOutput),
+    sourceMapUrl: args.sourcemapOutput && path.basename(args.sourcemapOutput),
     dev: args.dev,
     minify: !args.dev,
     platform: args.platform,