diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8b1ca8d..1b2d06d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -46,7 +46,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-latest, macos-latest, macos-10.15, windows-latest]
         python-version: ["3.6", "3.7", "3.8", "3.9", "3.10", "3.11-dev", "pypy-3.6", "pypy-3.7", "pypy-3.8"]
 
     name: Test
@@ -57,6 +57,7 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Set up Python ${{ matrix.python-version }}
+        if: ${{ matrix.os }} != "macos-latest" && ${{ matrix.python_version }} != "pypy-3.6"
         uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python-version }}