diff --git a/usr.sbin/bsdinstall/scripts/config b/usr.sbin/bsdinstall/scripts/config
index c3962443c9d..3ddcadaa895 100755
--- a/usr.sbin/bsdinstall/scripts/config
+++ b/usr.sbin/bsdinstall/scripts/config
@@ -39,7 +39,7 @@ rm $BSDINSTALL_TMPBOOT/loader.conf.*
 
 cp $BSDINSTALL_TMPBOOT/* $BSDINSTALL_CHROOT/boot
 
-[ "$debugFile" ] && cp "$debugFile" $BSDINSTALL_CHROOT/var/log/
+[ "${debugFile#+}" ] && cp "${debugFile#+}" $BSDINSTALL_CHROOT/var/log/
 
 # Set up other things from installed config
 chroot $BSDINSTALL_CHROOT /usr/bin/newaliases