diff --git a/.github/workflows/coding-standards.yml b/.github/workflows/coding-standards.yml
index ab319f77d6..e5117f737d 100644
--- a/.github/workflows/coding-standards.yml
+++ b/.github/workflows/coding-standards.yml
@@ -1,17 +1,21 @@
 name: Coding Standards
 
 on:
+  # JSHint was introduced in WordPress 3.8.
+  # PHPCS checking was introduced in WordPress 5.1.
   push:
     branches:
       - master
-      # JSHint was introduced in WordPress 3.8.
-      # PHPCS checking was introduced in WordPress 5.1.
       - '3.[89]'
       - '[4-9].[0-9]'
     tags:
       - '3.[89]*'
       - '[4-9].[0-9]*'
   pull_request:
+    branches:
+      - master
+      - '3.[89]'
+      - '[4-9].[0-9]'
 
 jobs:
   # Runs PHP coding standards checks.
diff --git a/.github/workflows/end-to-end-tests.yml b/.github/workflows/end-to-end-tests.yml
index 1dce7cd414..f99d5ead10 100644
--- a/.github/workflows/end-to-end-tests.yml
+++ b/.github/workflows/end-to-end-tests.yml
@@ -1,16 +1,20 @@
 name: End-to-end Tests
 
 on:
+  # The end to end test suite was introduced in WordPress 5.3.
   push:
     branches:
       - master
-      # The end to end test suite was introduced in WordPress 5.3.
       - '5.[3-9]'
       - '[6-9].[0-9]'
     tags:
       - '5.[3-9]*'
       - '[6-9].[0-9]*'
   pull_request:
+    branches:
+      - master
+      - '5.[3-9]'
+      - '[6-9].[0-9]'
 
 env:
   LOCAL_DIR: build
diff --git a/.github/workflows/javascript-tests.yml b/.github/workflows/javascript-tests.yml
index 3bfa95e2d9..b873c5ac33 100644
--- a/.github/workflows/javascript-tests.yml
+++ b/.github/workflows/javascript-tests.yml
@@ -1,16 +1,20 @@
 name: JavaScript Tests
 
 on:
+  # JavaScript testing was introduced in WordPress 3.8.
   push:
     branches:
       - master
-      # JavaScript testing was introduced in WordPress 3.8.
       - '3.[89]'
       - '[4-9].[0-9]'
     tags:
       - '3.[89]*'
       - '[4-9].[0-9]*'
   pull_request:
+    branches:
+      - master
+      - '3.[89]'
+      - '[4-9].[0-9]'
 
 jobs:
   # Runs the QUnit tests for WordPress.
diff --git a/.github/workflows/php-compatibility.yml b/.github/workflows/php-compatibility.yml
index d213c2612f..0506dad5b2 100644
--- a/.github/workflows/php-compatibility.yml
+++ b/.github/workflows/php-compatibility.yml
@@ -1,16 +1,20 @@
 name: PHP Compatibility
 
 on:
+  # PHP compatibility testing was introduced in WordPress 5.5.
   push:
     branches:
       - master
-      # The PHP compatibility testing was introduced in WordPress 5.5.
       - '5.[5-9]'
       - '[6-9].[0-9]'
     tags:
       - '5.[5-9]*'
       - '[6-9].[0-9]*'
   pull_request:
+    branches:
+      - master
+      - '5.[5-9]'
+      - '[6-9].[0-9]'
 
 jobs:
 
diff --git a/.github/workflows/phpunit-tests.yml b/.github/workflows/phpunit-tests.yml
index ae61625478..4d0cbea7c1 100644
--- a/.github/workflows/phpunit-tests.yml
+++ b/.github/workflows/phpunit-tests.yml
@@ -10,6 +10,10 @@ on:
       - '3.[7-9]*'
       - '[4-9].[0-9]*'
   pull_request:
+    branches:
+      - master
+      - '3.[7-9]'
+      - '[4-9].[0-9]'
   # Once weekly On Sundays at 00:00 UTC.
   schedule:
     - cron: '0 0 * * 0'
diff --git a/.github/workflows/verify-npm-on-windows.yml b/.github/workflows/verify-npm-on-windows.yml
index 70d2109539..fb4218c681 100644
--- a/.github/workflows/verify-npm-on-windows.yml
+++ b/.github/workflows/verify-npm-on-windows.yml
@@ -7,6 +7,10 @@ on:
       - '3.[7-9]'
       - '[4-9].[0-9]'
   pull_request:
+    branches:
+      - master
+      - '3.[7-9]'
+      - '[4-9].[0-9]'
 
 env:
   PUPPETEER_SKIP_CHROMIUM_DOWNLOAD: ${{ true }}