diff --git a/src/wp-includes/rest-api/class-wp-rest-server.php b/src/wp-includes/rest-api/class-wp-rest-server.php
index c7ffb5b7677d0..af12d02b51cb0 100644
--- a/src/wp-includes/rest-api/class-wp-rest-server.php
+++ b/src/wp-includes/rest-api/class-wp-rest-server.php
@@ -1007,7 +1007,11 @@ public function get_routes( $route_namespace = '' ) {
 				if ( is_string( $handler['methods'] ) ) {
 					$methods = explode( ',', $handler['methods'] );
 				} elseif ( is_array( $handler['methods'] ) ) {
-					$methods = $handler['methods'];
+					$methods = array();
+
+					foreach ( $handler['methods'] as $method ) {
+						$methods = array_merge( $methods, explode( ',', $method ) );
+					}
 				} else {
 					$methods = array();
 				}
diff --git a/tests/phpunit/tests/rest-api.php b/tests/phpunit/tests/rest-api.php
index fcb8e3da87f4c..0475b586d182d 100644
--- a/tests/phpunit/tests/rest-api.php
+++ b/tests/phpunit/tests/rest-api.php
@@ -362,6 +362,33 @@ public function test_route_method_comma_separated() {
 		);
 	}
 
+	/**
+	 * @ticket 65905
+	 */
+	public function test_route_method_array_with_comma_separated_values() {
+		register_rest_route(
+			'test-ns',
+			'/test',
+			array(
+				'methods'             => array( 'GET', 'POST, PUT, PATCH' ),
+				'callback'            => '__return_null',
+				'permission_callback' => '__return_true',
+			)
+		);
+
+		$routes = $GLOBALS['wp_rest_server']->get_routes();
+
+		$this->assertSame(
+			array(
+				'GET'   => true,
+				'POST'  => true,
+				'PUT'   => true,
+				'PATCH' => true,
+			),
+			$routes['/test-ns/test'][0]['methods']
+		);
+	}
+
 	public function test_options_request() {
 		register_rest_route(
 			'test-ns',