diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index a30ca4e..1c2d2fd 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -1,6 +1,12 @@
 name: Build / Release
 
-on: [push, pull_request]
+on:
+  push:
+    branches:
+      - 'master'
+  pull_request:
+    branches:
+      - '!deploy'
 
 jobs:
   release:
@@ -8,7 +14,7 @@ jobs:
 
     strategy:
       matrix:
-        os: [macos-latest, windows-latest, ubuntu-16.04]
+        os: [macos-latest, windows-latest, ubuntu-18.04]
 
     steps:
       - name: Check out Git repository