diff --git a/.github/workflows/upload-gh-pages.yml b/.github/workflows/upload-gh-pages.yml
index 59749595c..42a89c270 100644
--- a/.github/workflows/upload-gh-pages.yml
+++ b/.github/workflows/upload-gh-pages.yml
@@ -13,7 +13,7 @@ env:
 
 jobs:
   upload-doc:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2