diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 874feb4..5f1099f 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -128,6 +128,7 @@ jobs:
           environment-file: environment-dev.yml
           create-args: >-
             python=${{ matrix.python-version }}
+          micromamba-version: "1.5.10-0"  # pinned to avoid the breaking changes with mamba and micromamba (2.0.0).
       - name: Micromamba version
         run: |
           echo "micromamba $(micromamba --version)"