diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index 9a7c73e6..d4c83643 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -21,6 +21,8 @@ jobs:
 
     - name: Set up Python
       uses: actions/setup-python@v2
+      with:
+        python-version: '3.7'
 
     - name: Install PlatformIO
       run: |