diff --git a/tests/phpunit/tests/xmlrpc/mw/getPost.php b/tests/phpunit/tests/xmlrpc/mw/getPost.php
index 63d20b3ecd..9c914d708e 100644
--- a/tests/phpunit/tests/xmlrpc/mw/getPost.php
+++ b/tests/phpunit/tests/xmlrpc/mw/getPost.php
@@ -103,7 +103,6 @@ class Tests_XMLRPC_mw_getPost extends WP_XMLRPC_UnitTestCase {
 		$this->assertNotIXRError( $result );
 
 		$this->assertInternalType( 'int', $result['wp_post_thumbnail'] );
-		$this->assertStringMatchesFormat( '%d', $result['wp_post_thumbnail'] );
 		$this->assertEquals( $attachment_id, $result['wp_post_thumbnail'] );
 
 		remove_theme_support( 'post-thumbnails' );