diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d0ccc66d..3c828dc0 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -2,7 +2,7 @@ name: test
 on: [push, pull_request]
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     strategy:
       fail-fast: false
       matrix: