diff --git a/tests/build.yml b/tests/build.yml
index 0d89c5b8..4f6e33de 100644
--- a/tests/build.yml
+++ b/tests/build.yml
@@ -30,6 +30,10 @@ services:
     image: ${DOCKER_ORG:-mailu}/${DOCKER_PREFIX}radicale:${MAILU_VERSION:-local}
     build: ../optional/radicale
 
+  traefik-certdumper:
+    image: ${DOCKER_ORG:-mailu}/${DOCKER_PREFIX}traefik-certdumper:${MAILU_VERSION:-local}
+    build: ../optional/traefik-certdumper
+
   admin:
     image: ${DOCKER_ORG:-mailu}/${DOCKER_PREFIX}admin:${MAILU_VERSION:-local}
     build: ../core/admin