diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 15b6ac3..1351185 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -47,6 +47,7 @@ jobs:
         pytest --cov=mdit_py_plugins --cov-report=xml --cov-report=term-missing
     - name: Upload to Codecov
       uses: codecov/codecov-action@v3
+      if: github.event.pull_request.head.repo.full_name == github.repository
       with:
         token: ${{ secrets.CODECOV_TOKEN }}
         name: mdit-py-plugins-pytests