diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index a90ee948..8da3617d 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -130,7 +130,6 @@ jobs:
         python-version: ${{ matrix.cfg.python-version }}
         auto-activate-base: false
         show-channel-urls: true
-        use-mamba: true
         add-pip-as-python-dependency: true
         # note: conda-forge chnl req'd for Mambaforge, but we'll spec in file, not here `channels: conda-forge,...`
         # note: any activate/deactivate use the conda cmd. other cmds use mamba cmd.
@@ -166,8 +165,8 @@ jobs:
 
     - name: Environment Information
       run: |
-        mamba info
-        mamba list
+        conda info
+        conda list
 
     - name: Install QCEngine
       run: |
@@ -215,14 +214,13 @@ jobs:
         environment-file: devtools/conda-envs/${{ matrix.cfg.conda-env }}.yaml
         python-version: ${{ matrix.cfg.python-version }}
         auto-activate-base: false
-        use-mamba: true
         add-pip-as-python-dependency: true
         channels: conda-forge
 
     - name: Environment Information
       run: |
-        mamba info
-        mamba list --show-channel-urls
+        conda info
+        conda list --show-channel-urls
 
     - name: Build Documentation
       run: |