diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index b5ff271f..4e0dabc8 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -8,7 +8,7 @@ jobs:
       - uses: actions/checkout@v1
       - uses: actions/setup-python@v1
         with:
-          python-version: 3.10
+          python-version: 3.9
       - run: python -m pip install --upgrade pip setuptools wheel
       - run: make install
       - run: make pycodestyle
@@ -23,7 +23,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macOS-latest, windows-latest]
-        python-version: [3.6, 3.7, 3.8, 3.9, 3.10]
+        python-version: [3.6, 3.7, 3.8, 3.9]
     steps:
       - uses: actions/checkout@v1
       - uses: actions/setup-python@v1