diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 983ebb6..8c0cc55 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -24,6 +24,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install -r requirements-dev.txt
+        pip install -e .
         mypy --install-types
 
     - name: Validate against psf/black