diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index f31f3f6..ba76818 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -5,6 +5,8 @@ on:
       - main
     tags: ['*']
   pull_request:
+    branches:
+      - main
 concurrency:
   # Skip intermediate builds: always.
   # Cancel intermediate builds: only if it is a pull request build.