diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index f4a976a..07dd5ac 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -43,7 +43,7 @@ jobs:
       run: python3 tools/check_c_cpp_properties.py
 
   build_simulator:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
     - name: Install Arduino CLI
       uses: arduino/setup-arduino-cli@v1.1.1