diff --git a/src/wp-includes/embed-functions.php b/src/wp-includes/embed-functions.php
index 4bd142a42a..85dd095ca7 100644
--- a/src/wp-includes/embed-functions.php
+++ b/src/wp-includes/embed-functions.php
@@ -663,10 +663,6 @@ function _oembed_rest_pre_serve_request( $served, $result, $request, $server ) {
 	// Embed links inside the request.
 	$data = $server->response_to_data( $result, false );
 
-	if ( 404 === $result->get_status() ) {
-		$data = $data[0];
-	}
-
 	if ( ! class_exists( 'SimpleXMLElement' ) ) {
 		status_header( 501 );
 		die( get_status_header_desc( 501 ) );
diff --git a/tests/phpunit/tests/oembed/controller.php b/tests/phpunit/tests/oembed/controller.php
index 9410e00fa0..5cca6967ff 100644
--- a/tests/phpunit/tests/oembed/controller.php
+++ b/tests/phpunit/tests/oembed/controller.php
@@ -94,7 +94,7 @@ class Test_oEmbed_Controller extends WP_UnitTestCase {
 		$response = $this->server->dispatch( $request );
 		$data     = $response->get_data();
 
-		$this->assertEquals( 'rest_no_route', $data[0]['code'] );
+		$this->assertEquals( 'rest_no_route', $data['code'] );
 	}
 
 	function test_request_without_url_param() {
@@ -103,8 +103,8 @@ class Test_oEmbed_Controller extends WP_UnitTestCase {
 		$response = $this->server->dispatch( $request );
 		$data     = $response->get_data();
 
-		$this->assertEquals( 'rest_missing_callback_param', $data[0]['code'] );
-		$this->assertEquals( 'url', $data[0]['data']['params'][0] );
+		$this->assertEquals( 'rest_missing_callback_param', $data['code'] );
+		$this->assertEquals( 'url', $data['data']['params'][0] );
 	}
 
 	function test_request_with_bad_url() {
@@ -114,7 +114,7 @@ class Test_oEmbed_Controller extends WP_UnitTestCase {
 		$response = $this->server->dispatch( $request );
 		$data     = $response->get_data();
 
-		$this->assertEquals( 'oembed_invalid_url', $data[0]['code'] );
+		$this->assertEquals( 'oembed_invalid_url', $data['code'] );
 	}
 
 	function test_request_invalid_format() {
diff --git a/tests/phpunit/tests/rest-api/rest-server.php b/tests/phpunit/tests/rest-api/rest-server.php
index 2ec561a032..54a81a91c0 100644
--- a/tests/phpunit/tests/rest-api/rest-server.php
+++ b/tests/phpunit/tests/rest-api/rest-server.php
@@ -246,10 +246,9 @@ class Tests_REST_Server extends WP_Test_REST_TestCase {
 		$this->assertEquals( 500, $response->get_status() );
 
 		$data = $response->get_data();
-		$this->assertCount( 1, $data );
 
-		$this->assertEquals( $code,    $data[0]['code'] );
-		$this->assertEquals( $message, $data[0]['message'] );
+		$this->assertEquals( $code,    $data['code'] );
+		$this->assertEquals( $message, $data['message'] );
 	}
 
 	public function test_error_to_response_with_status() {
@@ -263,18 +262,15 @@ class Tests_REST_Server extends WP_Test_REST_TestCase {
 		$this->assertEquals( 400, $response->get_status() );
 
 		$data = $response->get_data();
-		$this->assertCount( 1, $data );
 
-		$this->assertEquals( $code,    $data[0]['code'] );
-		$this->assertEquals( $message, $data[0]['message'] );
+		$this->assertEquals( $code,    $data['code'] );
+		$this->assertEquals( $message, $data['message'] );
 	}
 
 	public function test_rest_error() {
 		$data = array(
-			array(
-				'code'    => 'wp-api-test-error',
-				'message' => 'Message text',
-			),
+			'code'    => 'wp-api-test-error',
+			'message' => 'Message text',
 		);
 		$expected = wp_json_encode( $data );
 		$response = $this->server->json_error( 'wp-api-test-error', 'Message text' );
@@ -292,10 +288,8 @@ class Tests_REST_Server extends WP_Test_REST_TestCase {
 		     ->with( $this->equalTo( 400 ) );
 
 		$data = array(
-			array(
-				'code'    => 'wp-api-test-error',
-				'message' => 'Message text',
-			),
+			'code'    => 'wp-api-test-error',
+			'message' => 'Message text',
 		);
 		$expected = wp_json_encode( $data );
 
@@ -417,9 +411,9 @@ class Tests_REST_Server extends WP_Test_REST_TestCase {
 		$this->assertCount( 1, $up );
 
 		$up_data = $up[0];
-		$this->assertEquals( 'wp-api-test-error', $up_data[0]['code'] );
-		$this->assertEquals( 'Test message',      $up_data[0]['message'] );
-		$this->assertEquals( 403, $up_data[0]['data']['status'] );
+		$this->assertEquals( 'wp-api-test-error', $up_data['code'] );
+		$this->assertEquals( 'Test message',      $up_data['message'] );
+		$this->assertEquals( 403, $up_data['data']['status'] );
 	}
 
 	/**