diff --git a/core/modules/system/src/Tests/Theme/ThemeTest.php b/core/modules/system/src/Tests/Theme/ThemeTest.php
index 1ddb3d8..e7e49c3 100644
--- a/core/modules/system/src/Tests/Theme/ThemeTest.php
+++ b/core/modules/system/src/Tests/Theme/ThemeTest.php
@@ -287,7 +287,8 @@ function testRegionClass() {
     // Place a block.
     $this->drupalPlaceBlock('system_main_block');
     $this->drupalGet('');
-    $elements = $this->cssSelect("new_class");
-    $this->assertRaw('new_class', 'New class found.');
+    $elements = $this->cssSelect("div.new_class");
+    debug($elements);
+    $this->assertEqual(count($elements), 1, 'New class found.');
   }
 }