diff --git a/.github/workflows/delete_merged_branch.yml b/.github/workflows/delete_merged_branch.yml
index 695aed69e..47fe8d703 100644
--- a/.github/workflows/delete_merged_branch.yml
+++ b/.github/workflows/delete_merged_branch.yml
@@ -7,7 +7,7 @@ on:
 jobs:
   delete_merged_branch:
     runs-on: ubuntu-latest
-    if: github.event.pull_request.merged == true
+    if: github.event.pull_request.merged == true && github.repository == github.event.pull_request.head.repo.full_name
     steps:
       - name: Checkout repository
         uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4