diff --git a/runtime/ftplugin/csc.vim b/runtime/ftplugin/csc.vim
index ac02088..3a09c3b 100644
--- a/runtime/ftplugin/csc.vim
+++ b/runtime/ftplugin/csc.vim
@@ -24,3 +24,4 @@
 
 " Restore the saved compatibility options.
 let &cpo = s:save_cpo
+unlet s:save_cpo