diff --git a/patchfile.gemspec b/patchfile.gemspec
index afb3ca1..e8db3ee 100644
--- a/patchfile.gemspec
+++ b/patchfile.gemspec
@@ -90,6 +90,7 @@ begin
     puts "finish change application_helper.rb in #{ENV['PWD']}/app/helpers/"
 rescue
     puts "Permission denied in #{ENV['PWD']}/app/helpers/application_helper.rb"
+    f.close
 end
 begin
   Site.first.update(:display_title_in_frontend=>false)