diff --git a/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php
index 350fa51..18a2288 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php
@@ -68,7 +68,7 @@ protected function setUp() {
     }
 
     // Set user agent to be consistent with WebTestBase.
-    $_SERVER['HTTP_USER_AGENT'] = $this->databasePrefix;
+    //$_SERVER['HTTP_USER_AGENT'] = $this->databasePrefix;
 
     $this->setup = TRUE;
   }