diff --git a/.github/workflows/build-and-test.yaml b/.github/workflows/build-and-test.yaml
index d5bf01c..45dc7a7 100644
--- a/.github/workflows/build-and-test.yaml
+++ b/.github/workflows/build-and-test.yaml
@@ -2,7 +2,8 @@
 on: [push]
 jobs:
   build:
-    runs-on: ubuntu-latest
+    # ubuntu-22 doesn't support Python 3.6
+    runs-on: ubuntu-20.04
     strategy:
       matrix:
         python-version: ["3.6", "3.7", "3.8", "3.9", "3.10"]