diff --git a/archive.gemspec b/archive.gemspec
index f9f9d7b..e208719 100644
--- a/archive.gemspec
+++ b/archive.gemspec
@@ -10,12 +10,12 @@ if bundle_update_flag
     require ::File.expand_path('app/helpers/bundler_helper.rb',  env_pwd)
     extend BundlerHelper
   rescue LoadError
-    def bundler_with_clean_env
+    def bundler_with_clean_env(&block)
       if block_given?
         if Bundler.respond_to?(:with_unbundled_env)
-          Bundler.with_unbundled_env(&Proc.new)
+          Bundler.with_unbundled_env(&block)
         else
-          Bundler.with_clean_env(&Proc.new)
+          Bundler.with_clean_env(&block)
         end
       end
     end