diff --git a/core/lib/Drupal/Component/Utility/UrlHelper.php b/core/lib/Drupal/Component/Utility/UrlHelper.php
index 553a152..3c29d40 100644
--- a/core/lib/Drupal/Component/Utility/UrlHelper.php
+++ b/core/lib/Drupal/Component/Utility/UrlHelper.php
@@ -37,13 +37,17 @@ class UrlHelper {
    * @ingroup php_wrappers
    */
   public static function buildQuery(array $query) {
-    // Previous versions of Drupal created query arguments with NULL values but
-    // http_build_query throws them away. This provides an equivalent
-    // functionality.
+    // Do some conversions to match previous implementations.
     array_walk_recursive($query, function (&$value, $key) {
+      // Previous versions of Drupal created query arguments with NULL values
+      // but http_build_query throws them away. Convert to empty string.
       if (!isset($value)) {
         $value = '';
       }
+      // Previous versions of Drupal cast objects to strings.
+      if (!is_scalar($value)) {
+        $value = (string) $value;
+      }
     });
     return http_build_query($query, '', '&', PHP_QUERY_RFC3986);
   }
diff --git a/core/modules/system/src/Tests/Database/SelectTableSortDefaultTest.php b/core/modules/system/src/Tests/Database/SelectTableSortDefaultTest.php
index 7ccbbb5..f1505c8 100644
--- a/core/modules/system/src/Tests/Database/SelectTableSortDefaultTest.php
+++ b/core/modules/system/src/Tests/Database/SelectTableSortDefaultTest.php
@@ -32,8 +32,8 @@ function testTableSortQuery() {
       $first = array_shift($data->tasks);
       $last = array_pop($data->tasks);
 
-      $this->assertEqual($first->task, $sort['first'], 'Items appear in the correct order.');
-      $this->assertEqual($last->task, $sort['last'], 'Items appear in the correct order.');
+      $this->assertEqual($first->task, $sort['first'], format_string('Items appear in the correct order sorting by @field @sort.', array('@field' => $sort['field'], '@sort' => $sort['sort'])));
+      $this->assertEqual($last->task, $sort['last'], format_string('Items appear in the correct order sorting by @field @sort.', array('@field' => $sort['field'], '@sort' => $sort['sort'])));
     }
   }
 
diff --git a/core/tests/Drupal/Tests/Component/Utility/UrlHelperTest.php b/core/tests/Drupal/Tests/Component/Utility/UrlHelperTest.php
index 3e7fe6c..93fe7dd 100644
--- a/core/tests/Drupal/Tests/Component/Utility/UrlHelperTest.php
+++ b/core/tests/Drupal/Tests/Component/Utility/UrlHelperTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\Component\Utility;
 
+use Drupal\Component\Render\FormattableMarkup;
 use Drupal\Component\Utility\UrlHelper;
 use Drupal\Tests\UnitTestCase;
 
@@ -49,6 +50,10 @@ public function testBuildQuerySpecial() {
     // Parse string throws away the leading space in the key breaking our
     // generalized test.
     $this->assertEquals('%20%26%23%2F%2F%2B%2520%40%DB%9E=a', UrlHelper::buildQuery([' &#//+%20@۞' => 'a']), 'Key was properly encoded.');
+
+    // Ensure as a convenience we can put translatable and formatted markup
+    // objects into queries.
+    $this->assertEquals('a=foo', UrlHelper::buildQuery(['a' => new FormattableMarkup('foo', [])]), 'Objects cast as a string.');
   }
 
   /**