diff --git a/tests/phpunit/includes/abstract-testcase.php b/tests/phpunit/includes/abstract-testcase.php
index 79276c0174..bbc365f671 100644
--- a/tests/phpunit/includes/abstract-testcase.php
+++ b/tests/phpunit/includes/abstract-testcase.php
@@ -181,19 +181,25 @@ abstract class WP_UnitTestCase_Base extends PHPUnit\Framework\TestCase {
 	/**
 	 * Allow tests to be skipped on some automated runs.
 	 *
-	 * For test runs on Travis for something other than trunk/master
-	 * we want to skip tests that only need to run for master.
+	 * For test runs on Travis/GitHub Actions for something other than trunk/master, we want to skip tests that
+	 * only need to run for master.
 	 */
 	public function skipOnAutomatedBranches() {
 		// https://docs.travis-ci.com/user/environment-variables/#Default-Environment-Variables
 		$travis_branch       = getenv( 'TRAVIS_BRANCH' );
 		$travis_pull_request = getenv( 'TRAVIS_PULL_REQUEST' );
 
-		if ( ! $travis_branch || ! $travis_pull_request ) {
+		// https://docs.github.com/en/free-pro-team@latest/actions/reference/environment-variables#default-environment-variables
+		$github_event_name = getenv( 'GITHUB_EVENT_NAME' );
+		$github_ref        = getenv( 'GITHUB_REF' );
+
+		if ( ( ! $travis_branch || ! $travis_pull_request ) && ! $github_event_name ) {
 			return;
 		}
 
-		if ( 'master' !== $travis_branch || 'false' !== $travis_pull_request ) {
+		if ( ( 'master' !== $travis_branch || 'false' !== $travis_pull_request ) && empty( $github_event_name ) ) {
+			$this->markTestSkipped( 'For automated test runs, this test is only run on trunk/master' );
+		} elseif ( in_array( $github_event_name, array( 'pull_request', 'pull_request_target' ), true ) || 'refs/heads/master' !== $github_ref ) {
 			$this->markTestSkipped( 'For automated test runs, this test is only run on trunk/master' );
 		}
 	}