diff --git a/tests/includes/listener-loader.php b/tests/includes/listener-loader.php
index 3ce669c6b48..030a77f9c14 100644
--- a/tests/includes/listener-loader.php
+++ b/tests/includes/listener-loader.php
@@ -6,4 +6,42 @@
  */
 
 $wp_tests_dir = getenv( 'WP_TESTS_DIR' ) ? getenv( 'WP_TESTS_DIR' ) : '/tmp/wordpress-tests-lib';
-require_once $wp_tests_dir . '/includes/listener-loader.php';
+
+/**
+ * The listener-loader.php file wasn't introduced into the core test framework until r44701, which
+ * means it came after WordPress 5.0 (r43971).
+ *
+ * Once WordPress 5.0 is no longer supported, we can safely reduce this to:
+ *
+ *   require_once $wp_tests_dir . '/includes/listener-loader.php';
+ *
+ * @link https://core.trac.wordpress.org/changeset/44701/
+ */
+if ( file_exists( $wp_tests_dir . '/includes/listener-loader.php' ) ) {
+	require_once $wp_tests_dir . '/includes/listener-loader.php';
+} else {
+	if ( version_compare( tests_get_phpunit_version(), '7.0', '>=' ) ) {
+		require $wp_tests_dir . '/includes/phpunit7/speed-trap-listener.php';
+	} else {
+		require $wp_tests_dir . '/includes/speed-trap-listener.php';
+	}
+}
+
+// Polyfill a function that wasn't added until WordPress 5.1.
+if ( ! function_exists( 'tests_get_phpunit_version' ) ) {
+	/**
+	 * Retrieves PHPUnit runner version.
+	 */
+	function tests_get_phpunit_version() {
+		if ( class_exists( 'PHPUnit_Runner_Version' ) ) {
+			$version = PHPUnit_Runner_Version::id();
+		} elseif ( class_exists( 'PHPUnit\Runner\Version' ) ) {
+			// Must be parsable by PHP 5.2.x.
+			$version = call_user_func( 'PHPUnit\Runner\Version::id' );
+		} else {
+			$version = 0;
+		}
+
+		return $version;
+	}
+}