diff --git a/.github/workflows/CI.yaml b/.github/workflows/CI.yaml
index 3903b89..557b115 100644
--- a/.github/workflows/CI.yaml
+++ b/.github/workflows/CI.yaml
@@ -38,6 +38,7 @@ jobs:
       # More info on options: https://github.com/mamba-org/provision-with-micromamba#migration-to-setup-micromamba%60
       - uses: mamba-org/setup-micromamba@v1
         with:
+          micromamba-version: '1.5.10-0'
           environment-file: devtools/conda-envs/test_env.yaml
           environment-name: test
           # channels: conda-forge,defaults