diff --git a/modules/@angular/core/src/di/reflective_exceptions.ts b/modules/@angular/core/src/di/reflective_exceptions.ts
index 1e4af7d049..9915001c81 100644
--- a/modules/@angular/core/src/di/reflective_exceptions.ts
+++ b/modules/@angular/core/src/di/reflective_exceptions.ts
@@ -175,8 +175,7 @@ export class InstantiationError extends WrappedException {
  */
 export class InvalidProviderError extends BaseException {
   constructor(provider) {
-    super("Invalid provider - only instances of Provider and Type are allowed, got: " +
-          provider.toString());
+    super(`Invalid provider - only instances of Provider and Type are allowed, got: ${provider}`);
   }
 }