diff --git a/backbone/backbone-global.d.ts b/backbone/backbone-global.d.ts
index 3d27e35b5c..3dca269eb0 100644
--- a/backbone/backbone-global.d.ts
+++ b/backbone/backbone-global.d.ts
@@ -153,7 +153,14 @@ declare namespace Backbone {
         /*private*/ set(attributeName: string, value: any, options?: ModelSetOptions): Model;
         set(obj: any, options?: ModelSetOptions): Model;
 
-        changedAttributes(attributes?: any): any | boolean;
+        /**
+         * Return an object containing all the attributes that have changed, or
+         * false if there are no changed attributes. Useful for determining what
+         * parts of a view need to be updated and/or what attributes need to be
+         * persisted to the server. Unset attributes will be set to undefined.
+         * You can also pass an attributes object to diff against the model,
+         * determining if there *would be* a change. */
+        changedAttributes(attributes?: any): any;
         clear(options?: Silenceable): any;
         clone(): Model;
         destroy(options?: ModelDestroyOptions): any;
diff --git a/backbone/backbone.d.ts b/backbone/backbone.d.ts
index 65e273a61f..d3887b4176 100644
--- a/backbone/backbone.d.ts
+++ b/backbone/backbone.d.ts
@@ -1,4 +1,4 @@
-// Type definitions for Backbone 1.0.0
+// Type definitions for Backbone 1.3.3
 // Project: http://backbonejs.org/
 // Definitions by: Boris Yankov <https://github.com/borisyankov/>, Natan Vivo <https://github.com/nvivo/>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped