diff --git a/.github/workflows/node.js.yml b/.github/workflows/node.js.yml
index 6dc339e..9a3691c 100644
--- a/.github/workflows/node.js.yml
+++ b/.github/workflows/node.js.yml
@@ -4,15 +4,19 @@
 name: Node.js CI
 
 on:
+  # Trigger the workflow on push or pull request,
+  # but only for the main branch
   push:
-    branches: [ main ]
+    branches:
+      - main
   pull_request:
-    branches: [ main ]
+    branches:
+      - main
 
 jobs:
   build:
 
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
 
     strategy:
       matrix: