diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 925513d..b81638f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -76,5 +76,8 @@ jobs:
 
       - name: Run tests
         shell: bash
+        env:
+          PYBIND11_BRANCH: "${{ matrix.pybind11 }}"
+          STUBS_SUB_DIR: "stubs/python-${{ matrix.python }}/pybind11-${{ matrix.pybind11 }}"
         run: >
-          tests/run-tests.sh --pybind11-branch "${{ matrix.pybind11 }}" --stubs-sub-dir "stubs/python-${{ matrix.python }}/pybind11-${{ matrix.pybind11 }}"
+          tests/run-tests.sh --pybind11-branch "$PYBIND11_BRANCH" --stubs-sub-dir "$STUBS_SUB_DIR"