diff --git a/actionpack/lib/action_view/helpers/asset_tag_helper.rb b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
index 6dd52d8186f..2f8b28c82b5 100644
--- a/actionpack/lib/action_view/helpers/asset_tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
@@ -385,7 +385,7 @@ module ActionView
       #  image_tag("mouse.png", :mouseover => image_path("mouse_over.png")) # =>
       #    <img src="/images/mouse.png" onmouseover="this.src='/images/mouse_over.png'" onmouseout="this.src='/images/mouse.png'" alt="Mouse" />
       def image_tag(source, options={})
-        options = options.dup.symbolize_keys!
+        options = options.symbolize_keys
 
         src = options[:src] = path_to_image(source)
 
@@ -478,7 +478,7 @@ module ActionView
         end
 
         def multiple_sources_tag(type, sources)
-          options = sources.extract_options!.dup.symbolize_keys!
+          options = sources.extract_options!.symbolize_keys
           sources.flatten!
 
           yield options if block_given?