diff --git a/packages/core/src/render3/interfaces/injector.ts b/packages/core/src/render3/interfaces/injector.ts
index e524ce38d4..ad2ef16d05 100644
--- a/packages/core/src/render3/interfaces/injector.ts
+++ b/packages/core/src/render3/interfaces/injector.ts
@@ -242,9 +242,7 @@ export class NodeInjectorFactory {
 }
 
 export function isFactory(obj: any): obj is NodeInjectorFactory {
-  // See: https://jsperf.com/instanceof-vs-getprototypeof
-  return obj !== null && typeof obj == 'object' &&
-      Object.getPrototypeOf(obj) == NodeInjectorFactory.prototype;
+  return obj instanceof NodeInjectorFactory;
 }
 
 // Note: This hack is necessary so we don't erroneously get a circular dependency