diff --git a/.github/workflows/macosx_cpn.yml b/.github/workflows/macosx_cpn.yml
index 35016433a..8beec064f 100644
--- a/.github/workflows/macosx_cpn.yml
+++ b/.github/workflows/macosx_cpn.yml
@@ -49,6 +49,11 @@ jobs:
         with:
           submodules: recursive
 
+      - name: Setup Python 3.9
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.9'
+
       - name: Create Build Environment
         # Some projects don't allow in-source building, so create a separate build directory
         # We'll use this as our working directory for all subsequent commands