diff --git a/.github/workflows/python-tests.yml b/.github/workflows/python-tests.yml
index d87bdf50..1107398b 100644
--- a/.github/workflows/python-tests.yml
+++ b/.github/workflows/python-tests.yml
@@ -24,7 +24,7 @@ jobs:
       - run: flake8 . --show-source
       - run: black --check --diff .
       - run: isort --check --diff .
-      - run: mypy .
+      - run: mypy optuna_dashboard python_tests
   test:
     runs-on: ubuntu-latest
     strategy: