diff --git a/.github/workflows/docker.yml b/.github/workflows/docker.yml
index 172f8d2f..e054ec31 100644
--- a/.github/workflows/docker.yml
+++ b/.github/workflows/docker.yml
@@ -1,16 +1,11 @@
 name: Docker
 on:
   push:
-    branches:
-      - master
-    paths-ignore:
-      - '.editorconfig'
-      - '.jenkins'
-      - '.jenkins.d/**'
-      - 'launchd/**'
-      - '.mailmap'
-      - 'systemd/**'
-      - 'tests/**'
+    tags:
+      - 'NFD-*'
+  schedule:
+    # twice a month
+    - cron: '20 8 5,20 * *'
   workflow_dispatch:
 
 permissions:
diff --git a/Dockerfile b/Dockerfile
index 0409463b..c2668812 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,6 +9,7 @@ RUN apt-get install -Uy --no-install-recommends \
     # use 'apt-get distclean' when we upgrade to ubuntu:24.04
     && rm -rf /var/lib/apt/lists/*
 
+ARG JOBS
 RUN --mount=type=bind,rw,target=/src <<EOF
 set -eux
 cd /src