diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index a86e5a2ac..54e8b1399 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -7,7 +7,7 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
     - name: checkout
       uses: actions/checkout@v1