diff --git a/coffee/chosen.jquery.coffee b/coffee/chosen.jquery.coffee
index 4ec7b22f14b..0c8cdebd86d 100644
--- a/coffee/chosen.jquery.coffee
+++ b/coffee/chosen.jquery.coffee
@@ -362,6 +362,10 @@ class Chosen extends AbstractChosen
 
       @form_field_jq.trigger "change", {'selected': @form_field.options[item.options_index].value} if @is_multiple || @form_field.selectedIndex != @current_selectedIndex
       @current_selectedIndex = @form_field.selectedIndex
+
+      evt.preventDefault()
+      evt.stopPropagation()
+
       this.search_field_scale()
 
   single_set_selected_text: (text=@default_text) ->
diff --git a/coffee/chosen.proto.coffee b/coffee/chosen.proto.coffee
index 199e2aa8e15..1322ed7a7cb 100644
--- a/coffee/chosen.proto.coffee
+++ b/coffee/chosen.proto.coffee
@@ -358,6 +358,9 @@ class @Chosen extends AbstractChosen
       @form_field.simulate("change") if typeof Event.simulate is 'function' && (@is_multiple || @form_field.selectedIndex != @current_selectedIndex)
       @current_selectedIndex = @form_field.selectedIndex
 
+      evt.preventDefault()
+      evt.stopPropagation()
+
       this.search_field_scale()
 
   single_set_selected_text: (text=@default_text) ->