diff --git a/.github/workflows/source-manifest.yml b/.github/workflows/source-manifest.yml
index e05ae34f..0131c066 100644
--- a/.github/workflows/source-manifest.yml
+++ b/.github/workflows/source-manifest.yml
@@ -98,7 +98,7 @@ jobs:
           path: SOURCE-MANIFEST.txt
 
       - name: Attach to release
-        if: startsWith(github.ref, 'refs/tags/')
+        if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/')
         env:
           GH_TOKEN: ${{ github.token }}
         run: |