diff --git a/modules/angular2/src/core/di/exceptions.ts b/modules/angular2/src/core/di/exceptions.ts
index 6e18ccf36b57..084b1a32ddef 100644
--- a/modules/angular2/src/core/di/exceptions.ts
+++ b/modules/angular2/src/core/di/exceptions.ts
@@ -222,8 +222,10 @@ export class NoAnnotationError extends BaseException {
         signature.push(parameter.map(stringify).join(' '));
       }
     }
-    return "Cannot resolve all parameters for " + stringify(typeOrFunc) + "(" +
-           signature.join(', ') + "). " + 'Make sure they all have valid type or annotations.';
+    return "Cannot resolve all parameters for '" + stringify(typeOrFunc) + "'(" +
+           signature.join(', ') + "). " +
+           "Make sure that all the parameters are decorated with Inject or have valid type annotations and that '" +
+           stringify(typeOrFunc) + "' is decorated with Injectable.";
   }
 }
 
diff --git a/modules/angular2/src/facade/lang.dart b/modules/angular2/src/facade/lang.dart
index bebddc051d6c..9323bff2371e 100644
--- a/modules/angular2/src/facade/lang.dart
+++ b/modules/angular2/src/facade/lang.dart
@@ -30,7 +30,15 @@ bool isPromise(obj) => obj is Future;
 bool isNumber(obj) => obj is num;
 bool isDate(obj) => obj is DateTime;
 
-String stringify(obj) => obj.toString();
+String stringify(obj) {
+  final exp = new RegExp(r"from Function '(\w+)'");
+  final str = obj.toString();
+  if (exp.firstMatch(str) != null) {
+    return exp.firstMatch(str).group(1);
+  } else {
+    return str;
+  }
+}
 
 int serializeEnum(val) {
   return val.index;
diff --git a/modules/angular2/test/core/di/injector_spec.ts b/modules/angular2/test/core/di/injector_spec.ts
index eed196dfe90b..41bc80970883 100644
--- a/modules/angular2/test/core/di/injector_spec.ts
+++ b/modules/angular2/test/core/di/injector_spec.ts
@@ -88,6 +88,8 @@ class NoAnnotations {
   constructor(secretDependency) {}
 }
 
+function factoryFn(a) {}
+
 export function main() {
   var dynamicProviders = [
     provide('provider0', {useValue: 1}),
@@ -142,10 +144,20 @@ export function main() {
         expect(car.engine).toBeAnInstanceOf(TurboEngine);
       });
 
-      it('should throw when no type and not @Inject', () => {
+      it('should throw when no type and not @Inject (class case)', () => {
         expect(() => createInjector([NoAnnotations]))
-            .toThrowError('Cannot resolve all parameters for NoAnnotations(?). ' +
-                          'Make sure they all have valid type or annotations.');
+            .toThrowError(
+                "Cannot resolve all parameters for 'NoAnnotations'(?). " +
+                'Make sure that all the parameters are decorated with Inject or have valid type annotations ' +
+                "and that 'NoAnnotations' is decorated with Injectable.");
+      });
+
+      it('should throw when no type and not @Inject (factory case)', () => {
+        expect(() => createInjector([provide("someToken", {useFactory: factoryFn})]))
+            .toThrowError(
+                "Cannot resolve all parameters for 'factoryFn'(?). " +
+                'Make sure that all the parameters are decorated with Inject or have valid type annotations ' +
+                "and that 'factoryFn' is decorated with Injectable.");
       });
 
       it('should cache instances', () => {