diff --git a/.github/workflows/branchbuild.yml b/.github/workflows/branchbuild.yml
index 844c1ef7..ca581fc7 100644
--- a/.github/workflows/branchbuild.yml
+++ b/.github/workflows/branchbuild.yml
@@ -148,6 +148,7 @@ jobs:
           submodules: 'true'
       - uses: "actions/setup-python@v5"
         with:
+          allow-prereleases: true
           python-version: "${{ matrix.python-version }}"
 
       - name: build