diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index b7529427e..61e3825ef 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -32,7 +32,7 @@ jobs:
 
       - uses: actions/setup-python@v4
         with:
-          python-version: "3.x"
+          python-version: "3.9"
 
       - name: Install PlatformIO
         run: |
@@ -77,7 +77,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v4
         with:
-          python-version: "3.x"
+          python-version: "3.9"
 
       - name: Install PlatformIO
         run: |