diff --git a/.github/workflows/python-tests.yml b/.github/workflows/python-tests.yml
index 07a5d8a..9f4081d 100644
--- a/.github/workflows/python-tests.yml
+++ b/.github/workflows/python-tests.yml
@@ -39,6 +39,7 @@ jobs:
           python -m pip install --upgrade pip setuptools_scm[toml] wheel setuptools
           python -m pip install --upgrade attrs types-attrs
           python -m pip install flake8 tox mypy
+          python -m pip install .
       - name: Mypy
         run: |
           mypy --cache-dir .mypy_cache --install-types --non-interactive ./src