diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index d528f33..aec72c1 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -16,7 +16,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: [3.7]
+        python-version: ['3.8', '*']  # Lowest and unbound version to test for.
         conda-channel: ['conda-forge', 'conda-canary/label/dev']
     steps:
     - uses: actions/checkout@v2
@@ -26,6 +26,7 @@ jobs:
         environment-file: tests/env.yml
         create-args: >-
           --channel-priority=flexible
+          python=${{ matrix.python-version }}
           ${{ matrix.conda-channel }}::conda
           ${{ matrix.conda-channel }}::conda-build
     - name: Install boa