diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c0e9aecb11bd96f1ae23e468e329888566df6379..dc5d8262cdb4c6d723a37b5c188f7b6af1314dce 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -12,6 +12,8 @@ flake8:
 
 build-docker-image:
   stage: build
+  only:
+    - master
   image:
     name: gitlab-registry.cern.ch/ci-tools/docker-image-builder
     entrypoint: [""]