diff --git a/packages/core/src/di/injector.ts b/packages/core/src/di/injector.ts
index e0286e80b4..0dedf6e2a4 100644
--- a/packages/core/src/di/injector.ts
+++ b/packages/core/src/di/injector.ts
@@ -34,7 +34,8 @@ export class NullInjector implements Injector {
     if (notFoundValue === _THROW_IF_NOT_FOUND) {
       // Intentionally left behind: With dev tools open the debugger will stop here. There is no
       // reason why correctly written application should cause this exception.
-      debugger;
+      // TODO(misko): uncomment the next line once `ngDevMode` works with closure.
+      // if(ngDevMode) debugger;
       throw new Error(`NullInjectorError: No provider for ${stringify(token)}!`);
     }
     return notFoundValue;