diff --git a/master/Dockerfile b/master/Dockerfile
index 3aac183..8bbf973 100644
--- a/master/Dockerfile
+++ b/master/Dockerfile
@@ -1,2 +1,2 @@
-FROM buildbot/buildbot-master:master
+FROM buildbot/buildbot-master:v3.11.5
 RUN /buildbot_venv/bin/pip3 install buildbot_gitea