diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index e6b29ef..1315659 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -1,5 +1,13 @@
 name: main
 
+# Automatically cancel a previous run.
+concurrency:
+  group: ${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+env:
+  CONDA_EXE: mamba
+
 on:
   push:
     branches:
@@ -8,10 +16,6 @@ on:
     branches:
     - '*'
 
-concurrency:
-  group: ${{ github.head_ref || github.run_id }}
-  cancel-in-progress: true
-
 jobs:
 
   run-tests:
@@ -23,19 +27,21 @@ jobs:
       fail-fast: false
       matrix:
         os: ['ubuntu-latest', 'macos-latest', 'windows-latest']
-        python-version: ['3.7', '3.8', '3.9', '3.10']
+        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11']
 
     steps:
       - uses: actions/checkout@v2
       - uses: r-lib/actions/setup-tinytex@v1
       - uses: conda-incubator/setup-miniconda@v2
         with:
-          auto-update-conda: true
+          auto-update-conda: false
           python-version: ${{ matrix.python-version }}
+          channels: conda-forge,nodefaults
+          mamba-version: "*"
 
       - name: Install core dependencies.
         shell: bash -l {0}
-        run: conda install -c conda-forge tox-conda coverage
+        run: mamba install -c conda-forge tox-conda coverage
 
       - name: Run end-to-end tests.
         shell: bash -l {0}