diff --git a/acme.sh b/acme.sh
index 47eb5a9a..01c889af 100755
--- a/acme.sh
+++ b/acme.sh
@@ -3056,7 +3056,7 @@ _checkConf() {
       _debug "Try include files"
       for included in $(cat "$2" | tr "\t" " " | grep "^ *include *.*;" | sed "s/include //" | tr -d " ;"); do
         _debug "check included $included"
-        if !_startswith "$included" "/" && _exists dirname; then
+        if ! _startswith "$included" "/" && _exists dirname; then
           _relpath="$(dirname "$_c_file")"
           _debug "_relpath" "$_relpath"
           included="$_relpath/included"