diff --git a/.github/workflows/pr_test_build.yml b/.github/workflows/pr_test_build.yml
index c98e9604a..190b891e1 100644
--- a/.github/workflows/pr_test_build.yml
+++ b/.github/workflows/pr_test_build.yml
@@ -7,7 +7,7 @@ on:
 jobs:
   test:
 
-    runs-on: ubuntu-20.04(ubuntu-latest)
+    runs-on: ubuntu-18.04
 
     steps:
       - uses: actions/checkout@v2