diff --git a/packages/core/src/util/ng_dev_mode.ts b/packages/core/src/util/ng_dev_mode.ts
index 7fb0579cb723e..a79f0af0f37c8 100644
--- a/packages/core/src/util/ng_dev_mode.ts
+++ b/packages/core/src/util/ng_dev_mode.ts
@@ -115,7 +115,7 @@ export function initNgDevMode(): boolean {
     if (typeof ngDevMode !== 'object') {
       ngDevModeResetPerfCounters();
     }
-    return !!ngDevMode;
+    return typeof ngDevMode !== 'undefined' && !!ngDevMode;
   }
   return false;
 }