diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f1c4fdd..7b252af 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -11,3 +11,5 @@ mirror:
   stage: triggers
   trigger:
     include: .gitlab/mirror.yml
+  rules:
+    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH
diff --git a/.gitlab/mirror.yml b/.gitlab/mirror.yml
index d99cafc..86a4021 100644
--- a/.gitlab/mirror.yml
+++ b/.gitlab/mirror.yml
@@ -17,8 +17,10 @@ pull-github:
   script:
     - whoami; env
 
+    - if [ -z "$CI_COMMIT_BRANCH" ]; then echo "Not on a branch" >&2; exit 3; fi
+
     - git remote remove github 2>/dev/null || true
     - git remote add github https://github.com/qurator-spk/dinglehopper.git
     - git remote -v
 
-    - git pull github master
+    - git pull github "$CI_COMMIT_BRANCH"