diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 98fc678..ffd9fb3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -3,13 +3,18 @@ name: CI
 on: [push, pull_request]
 
 jobs:
-  build:
-
-    runs-on: ubuntu-latest
+  checks:
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
+        os: [ubuntu-latest, ubuntu-20.04]
         python-version: [3.5, 3.9]
+        exclude:
+          - os: ubuntu-latest
+            python-version: 3.5
+          - os: ubuntu-20.04
+            python-version: 3.9
 
     steps:
     - uses: actions/checkout@v2