diff --git a/scripts/docker-setup.sh b/scripts/docker-setup.sh
index 0884728..6095f11 100644
--- a/scripts/docker-setup.sh
+++ b/scripts/docker-setup.sh
@@ -1288,7 +1288,7 @@ install_filebrowser() {
             [[ "$name" == .felhom-raw ]] && continue
             volume_lines+="      - \"${mp%/}:/srv/${name}\""$'\n'
             mount_comment+="      # ${mp%/} → /srv/${name}"$'\n'
-            ((found_mounts++))
+            found_mounts=$(( found_mounts + 1 ))
         done
     fi