diff --git a/docs/assets/bootstrap.zip b/docs/assets/bootstrap.zip
index d36eb3885e..24e5a31248 100644
Binary files a/docs/assets/bootstrap.zip and b/docs/assets/bootstrap.zip differ
diff --git a/docs/assets/js/bootstrap-collapse.js b/docs/assets/js/bootstrap-collapse.js
index d195efc727..2139d6703f 100644
--- a/docs/assets/js/bootstrap-collapse.js
+++ b/docs/assets/js/bootstrap-collapse.js
@@ -74,7 +74,9 @@
         [dimension](size || 'auto')
         [0].offsetWidth
 
-      this.$element.addClass('collapse')
+      this.$element[size ? 'addClass' : 'removeClass']('collapse')
+
+      return this
     }
 
   , transition: function ( method, startEvent, completeEvent ) {
diff --git a/js/bootstrap-collapse.js b/js/bootstrap-collapse.js
index d195efc727..2139d6703f 100644
--- a/js/bootstrap-collapse.js
+++ b/js/bootstrap-collapse.js
@@ -74,7 +74,9 @@
         [dimension](size || 'auto')
         [0].offsetWidth
 
-      this.$element.addClass('collapse')
+      this.$element[size ? 'addClass' : 'removeClass']('collapse')
+
+      return this
     }
 
   , transition: function ( method, startEvent, completeEvent ) {