diff --git a/angular-rx/rx.angular-tests.ts b/angular-rx/rx.angular-tests.ts
index f01d8e629..3caf01170 100644
--- a/angular-rx/rx.angular-tests.ts
+++ b/angular-rx/rx.angular-tests.ts
@@ -1,3 +1,8 @@
+// Type definitions for angularjs extensions to rxjs
+// Project: http://reactivex.io/
+// Definitions by: Mick Delaney <https://github.com/mickdelaney/>
+// Definitions: https://github.com/borisyankov/DefinitelyTyped
+
 /// <reference path="rx.angular.d.ts" />
 
 var app = angular.module('testModule');
diff --git a/angular-rx/rx.angular.d.ts b/angular-rx/rx.angular.d.ts
index f32933f6d..e2d0ec8c5 100644
--- a/angular-rx/rx.angular.d.ts
+++ b/angular-rx/rx.angular.d.ts
@@ -1,3 +1,8 @@
+// Type definitions for angularjs extensions to rxjs
+// Project: http://reactivex.io/
+// Definitions by: Mick Delaney <https://github.com/mickdelaney/>
+// Definitions: https://github.com/borisyankov/DefinitelyTyped
+
 /// <reference path="../angularjs/angular.d.ts" />
 /// <reference path="../rx/rx.d.ts" />
 /// <reference path="../rx/rx.time.d.ts" />
@@ -5,7 +10,7 @@
 declare module Rx {
 
     interface IObservable<T> {
-        safeApply($scope: ng.IScope, callback: (data: any) => void);
+        safeApply($scope: ng.IScope, callback: (data: any) => void): Rx.Observable<any>;
     }
 }