diff --git a/tests/phpunit/tests/rest-api/rest-server.php b/tests/phpunit/tests/rest-api/rest-server.php
index 0c148c21e3..188a8e6138 100644
--- a/tests/phpunit/tests/rest-api/rest-server.php
+++ b/tests/phpunit/tests/rest-api/rest-server.php
@@ -13,15 +13,20 @@ class Tests_REST_Server extends WP_Test_REST_TestCase {
 	public function setUp() {
 		parent::setUp();
 
-		/** @var WP_REST_Server $wp_rest_server */
-		global $wp_rest_server;
-
-		unset( $wp_rest_server );
+		// Reset REST server to ensure only our routes are registered
+		$GLOBALS['wp_rest_server'] = null;
 		add_filter( 'wp_rest_server_class', array( $this, 'filter_wp_rest_server_class' ) );
 		$this->server = rest_get_server();
 		remove_filter( 'wp_rest_server_class', array( $this, 'filter_wp_rest_server_class' ) );
 	}
 
+	public function tearDown() {
+		// Remove our temporary spy server
+		$GLOBALS['wp_rest_server'] = null;
+
+		parent::tearDown();
+	}
+
 	public function test_envelope() {
 		$data = array(
 			'amount of arbitrary data' => 'alot',