diff --git a/actionpack/lib/action_dispatch/http/response.rb b/actionpack/lib/action_dispatch/http/response.rb
index 9a10dc73d9..9b11111a67 100644
--- a/actionpack/lib/action_dispatch/http/response.rb
+++ b/actionpack/lib/action_dispatch/http/response.rb
@@ -413,7 +413,7 @@ module ActionDispatch # :nodoc:
 
     def before_sending
       headers.freeze
-      request.commit_cookie_jar!
+      request.commit_cookie_jar! unless committed?
     end
 
     def build_buffer(response, body)