diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 56727f5..2e05b68 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -5,6 +5,9 @@ concurrency:
   group: ${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
 
+env:
+  CONDA_EXE: mamba
+
 on:
   push:
     branches:
@@ -24,18 +27,20 @@ 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: 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
 
       # Unit, integration, and end-to-end tests.
 
@@ -56,8 +61,3 @@ jobs:
         if: runner.os == 'Linux' && matrix.python-version == '3.8'
         shell: bash -l {0}
         run: bash <(curl -s https://codecov.io/bash) -F end_to_end -c
-
-      - name: Validate codecov.yml
-        if: runner.os == 'Linux' && matrix.python-version == '3.8'
-        shell: bash -l {0}
-        run: cat codecov.yml | curl --data-binary @- https://codecov.io/validate