diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0398cbc49..beaf3ae03 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,7 +13,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: ["ubuntu-latest", "macos-latest"]
+        # macos-latest doesn't have 3.7 anymore or pypy-3.9 ..
+        os: ["ubuntu-latest", "macos-13"]
         python-version: ["3.7", "3.12", "pypy-3.9"]
         r-version: ['release']
     timeout-minutes: 60