diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 90ea2705..6e366c77 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -40,18 +40,27 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
 
+      - name: Prepare mamba installation        
+        env:
+          PYTHON_VERSION: ${{ matrix.python-version }}
+        run: |
+          # setup correct python version
+          sed -i -e "s/- python=.*/- python=$PYTHON_VERSION/g" environment.yml
+
+      - name: mamba setup
+        uses: mamba-org/setup-micromamba@v1
+        with:
+          environment-file: environment.yml
+          cache-downloads: true
       - name: Install dependencies
         env:
           PYTHON_VERSION: ${{ matrix.python-version }}
           CTAPIPE_VERSION: ${{ matrix.ctapipe-version }}
 
         run: |
-          . $CONDA/etc/profile.d/conda.sh
-          conda config --set always_yes yes --set changeps1 no
-          sed -i -e "s/- python=.*/- python=$PYTHON_VERSION/g" environment.yml
-          conda install mamba -n base -c conda-forge
+          
           mamba env create -n ci -f environment.yml
-          conda activate ci
+          mamba activate ci
           # we install ctapipe using pip to be able to select any commit, e.g. the current master
           pip install pytest-cov "git+https://github.com/cta-observatory/ctapipe@$CTAPIPE_VERSION"
           pip install pyflakes
@@ -73,8 +82,7 @@ jobs:
         run: |
           # github actions starts a new shell for each "step", so we need to
           # activate our env again
-          source $CONDA/etc/profile.d/conda.sh
-          conda activate ci
+          mamba activate ci
           coverage run -m pytest -v
           coverage xml