diff --git a/.github/workflows/docker-publish.yml b/.github/workflows/docker-publish.yml
index f1b3d0a..5c2c61d 100644
--- a/.github/workflows/docker-publish.yml
+++ b/.github/workflows/docker-publish.yml
@@ -13,7 +13,7 @@ on:
     # Publish semver tags as releases.
     tags: ["v*.*.*"]
   pull_request:
-    branches: ["{{is_default_branch}}"]
+    branches: [master]
   release:
     types: [published]