diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index f182b83..3509aa4 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -51,7 +51,7 @@ jobs:
         uses: conda-incubator/setup-miniconda@v3
         with:
           python-version: 3.8
-          mamba-version: "*"
+          mamba-version: 1.5.10
           channels: conda-forge,defaults
           channel-priority: true
           activate-environment: conda-env