diff --git a/plugin/fzf.vim b/plugin/fzf.vim
index 11159af..04f9643 100644
--- a/plugin/fzf.vim
+++ b/plugin/fzf.vim
@@ -519,7 +519,7 @@ finally
     if len(prev_default_command)
       let $FZF_DEFAULT_COMMAND = prev_default_command
     else
-      unlet $FZF_DEFAULT_COMMAND
+      execute 'unlet $FZF_DEFAULT_COMMAND'
     endif
   endif
   let [&shell, &shellslash, &shellcmdflag, &shellxquote] = [shell, shellslash, shellcmdflag, shellxquote]