diff --git a/Makefile b/Makefile
index e6e988f42..e3d9987b8 100644
--- a/Makefile
+++ b/Makefile
@@ -300,7 +300,7 @@ updateSemver: # unless the package.json has been manually edited.
 	git diff --quiet -- package.json && node build/incrementSemver.js
 
 dist/commonjs: bin/traceur.js
-	./traceur --dir src/ dist/commonjs/ --modules=commonjs
+	./traceur --dir src/ dist/commonjs/ --modules=commonjs --require-runtime
 
 prepublish: bin/traceur.js bin/traceur-runtime.js dist/commonjs/