diff --git a/.woodpecker.yaml b/.woodpecker.yaml
index 1de67dd..de96fa3 100644
--- a/.woodpecker.yaml
+++ b/.woodpecker.yaml
@@ -1,13 +1,19 @@
-nch: main
-
 steps:
+  - name: HTML syntax check
   - name: build
+    image: debian:12
     image: debian
+    # Debian has tidy 5.6.0, which complains about the "loading" tag in img.
+    # We need a more recent version for now.
     commands:
+    commands:
+      - DEBIAN_FRONTEND=noninteractive apt update -qq
       - echo "This is the build step"
+      - DEBIAN_FRONTEND=noninteractive apt install -qq -y wget
       - echo "binary-data-123" > executable
+      - wget -q https://github.com/htacg/tidy-html5/releases/download/5.8.0/tidy-5.8.0-Linux-64bit.deb
   - name: a-test-step
+      - echo "59e594312207234f5a17455683c13c6bc47a89cb7bf994d493acfffb591d9830 tidy-5.8.0-Linux-64bit.deb" | sha256sum -c
     image: golang:1.16
-    commands:
-      - echo "Testing ..."
-      - ./executable
+      - DEBIAN_FRONTEND=noninteractive apt install -qq -y ./tidy-5.8.0-Linux-64bit.deb
+      - tidy -q -e --drop-empty-elements no static/index.html