diff --git a/runtime/ftplugin/php.vim b/runtime/ftplugin/php.vim
index f59cf12..93de5b9 100644
--- a/runtime/ftplugin/php.vim
+++ b/runtime/ftplugin/php.vim
@@ -80,3 +80,4 @@
 
 " Restore the saved compatibility options.
 let &cpo = s:save_cpo
+unlet s:save_cpo