diff --git a/.github/workflows/unittest-flux-mpich.yml b/.github/workflows/unittest-flux-mpich.yml
index fe929d67..7d2b5b76 100644
--- a/.github/workflows/unittest-flux-mpich.yml
+++ b/.github/workflows/unittest-flux-mpich.yml
@@ -19,7 +19,7 @@ jobs:
         echo -e "channels:\n  - conda-forge\n" > .condarc
     - uses: conda-incubator/setup-miniconda@v3
       with:
-        python-version: '3.13'
+        python-version: '3.12'
         miniforge-version: latest
         condarc-file: .condarc
         environment-file: .ci_support/environment-mpich.yml