diff --git a/.github/workflows/build-images.yml b/.github/workflows/build-images.yml
index 0eedeb19d7cbd..f14d9d7a28a7d 100644
--- a/.github/workflows/build-images.yml
+++ b/.github/workflows/build-images.yml
@@ -19,6 +19,8 @@
 name: "Build Images"
 on:  # yamllint disable-line rule:truthy
   pull_request_target:
+    branches:
+      - main
 permissions:
   # all other permissions are set to none
   contents: read