diff --git a/src/core/di/provider_util.ts b/src/core/di/provider_util.ts
index e6e0b7c..f471124 100644
--- a/src/core/di/provider_util.ts
+++ b/src/core/di/provider_util.ts
@@ -41,16 +41,16 @@ function _hasTemplate( annotation: any ): boolean {
   return isPresent( annotation.template || annotation.templateUrl );
 }
 
-export function isService(annotation: any): annotation is InjectableMetadata {
+export function isService( annotation: any ): annotation is InjectableMetadata {
   return annotation instanceof InjectableMetadata;
 }
-export function isPipe(annotation: any): annotation is PipeMetadata {
-  return isString(annotation.name) && annotation instanceof PipeMetadata;
+export function isPipe( annotation: any ): annotation is PipeMetadata {
+  return isString( annotation.name ) && annotation instanceof PipeMetadata;
 }
 export function isInjectMetadata( injectMeta: any ): injectMeta is InjectMetadata {
   return injectMeta instanceof InjectMetadata;
 }
 
 export function isNgModule( annotation: any ): annotation is NgModuleMetadata {
-  return isPresent( annotation.declarations ) && annotation instanceof NgModuleMetadata
+  return annotation instanceof NgModuleMetadata
 }
diff --git a/src/core/util/bundler.ts b/src/core/util/bundler.ts
index 3045679..016e002 100644
--- a/src/core/util/bundler.ts
+++ b/src/core/util/bundler.ts
@@ -58,7 +58,7 @@ export function bundle( NgModuleClass: Type, otherProviders: any[] = [], existin
   const annotations = reflector.annotations( NgModuleClass );
   const ngModuleAnnotation: NgModuleMetadata = annotations[ 0 ];
   if (!isNgModule(ngModuleAnnotation)) {
-    throw new Error(`bundle() requires an @NgModule as it's first argument`)
+    throw new Error(`bundle() requires a decorated NgModule as its first argument`)
   }
   const { declarations = [], providers = [], imports = [] }={} = ngModuleAnnotation;