diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 7f6d7f6..dacf8a5 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -8,7 +8,7 @@ on:
 jobs:
   pypi-publish:
     name: upload release to PyPI
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     permissions:
       contents: read
       id-token: write