diff --git a/.github/workflows/build_micropython.yml b/.github/workflows/build_micropython.yml
index e28de5f1e..a8bb91278 100644
--- a/.github/workflows/build_micropython.yml
+++ b/.github/workflows/build_micropython.yml
@@ -8,7 +8,7 @@ jobs:
   build:
     if: ${{ github.event_name != 'pull_request' || github.repository != github.event.pull_request.head.repo.full_name }}
     name: Build ${{ matrix.port }} port
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     continue-on-error: true
     strategy:
       matrix: