diff --git a/marionette/marionette.d.ts b/marionette/marionette.d.ts
index 870484b89..583a6becb 100644
--- a/marionette/marionette.d.ts
+++ b/marionette/marionette.d.ts
@@ -666,6 +666,11 @@ declare module Marionette {
 
         constructor(options?: Backbone.ViewOptions<TModel>);
 
+        /** 
+         * Defines behaviors attached to this view. 
+         */
+        behaviors: any;
+
         /**
          * A configuration hash for models. The left side is the event on 
          * the model, and the right side is the name of the 
@@ -692,7 +697,7 @@ declare module Marionette {
          * jQuery selector. Afterwards you can simply access it via 
          * this.ui.elementName.
          */
-        ui(): any;
+        ui: any;
 
         /**
          * There may be some cases where you need to change the template that is 
@@ -1255,6 +1260,85 @@ declare module Marionette {
         stopvoid;
         addDefinition(moduleDefinition, customArgs);
     }
+
+    /**
+     * A Behavior is an isolated set of DOM / user interactions that can be mixed 
+     * into any View or another Behavior. Behaviors allow you to blackbox View 
+     * specific interactions into portable logical chunks, keeping your views 
+     * simple and your code DRY.
+     */
+    class Behavior extends Marionette.Object {
+        constructor(options?: any, view?: any);
+
+        options: any;
+
+        /**
+         * Any triggers you define on the Behavior will be triggered in response to the appropriate event on the view.
+         */
+        triggers: any;
+
+        /**
+         * modelEvents will respond to the view's model events.
+         */
+        modelEvents: any;
+
+        /**
+         * collectionEvents will respond to the view's collection events.
+         */
+        collectionEvents: any;
+
+        /**
+         * The behaviors key allows a behavior to group multiple behaviors 
+         * together.
+         */
+        behaviors: any;
+
+        /**
+         * defaults can be a hash or function to define the default options for 
+         * your behavior. The default options will be overridden depending on 
+         * what you set as the options per behavior (this works just like a 
+         * backbone.model).
+         */
+        defaults: any;
+
+        /**
+         * el is a direct proxy of the view's el
+         */
+        el: any;
+
+        /**
+         * $el is a direct proxy of the view's el cached as a jQuery selector.
+         */
+        $el: JQuery;
+
+        /** A reference to the view instance that the behavior is on. */
+        view: any;
+
+        /**
+         * $ is a direct proxy of the views $ lookup method.
+         */
+        $(selector: any): JQuery;
+    }
+
+    /**
+     * Marionette.Behaviors' is a utility class that takes care of glueing your 
+     * behavior instances to their given View. The most important part of this 
+     * class is that you MUST override the class level behaviorsLookup method or 
+     * set the option behaviorClass for things to work properly.
+     */
+    class Behaviors {
+        /**
+         * This method defines where your behavior classes are stored. Override this to provide another lookup.
+         */
+        static behaviorsLookup(): any;
+
+        /**
+         * This method has a default implementation that is simple to override. It 
+         * is responsible for the lookup of single behavior from within the 
+         * Behaviors.behaviorsLookup or elsewhere.
+         */
+        static getBehaviorClass(options: any, key: string): Behavior;
+    }
 }
 
 declare module 'backbone.marionette' {