diff --git a/.github/workflows/ci_with_install.yml b/.github/workflows/ci_with_install.yml
index fef270e..2083bdf 100644
--- a/.github/workflows/ci_with_install.yml
+++ b/.github/workflows/ci_with_install.yml
@@ -22,7 +22,8 @@ jobs:
       
       - name: install package
         run: |
-          conda install -c conda-forge moab
+          conda install -c conda-forge -y mamba
+          mamba install -c conda-forge -y "openmc=0.13.0=dagmc*nompi*"
           pip install .
           python -c "import vertices_to_h5m"