diff --git a/core/modules/system/src/Tests/Path/UrlAlterFunctionalTest.php b/core/modules/system/src/Tests/Path/UrlAlterFunctionalTest.php
index 53e7b7a..78f3111 100644
--- a/core/modules/system/src/Tests/Path/UrlAlterFunctionalTest.php
+++ b/core/modules/system/src/Tests/Path/UrlAlterFunctionalTest.php
@@ -89,7 +89,7 @@ protected function assertUrlOutboundAlter($original, $final) {
     // Test outbound altering.
     $result = $this->container->get('url_generator')->generateFromPath($original);
     $final = Url::fromUri('internal:/' . $final)->toString();
-    $this->assertIdentical($result, $final, format_string('Altered outbound URL %original, expected %final, and got %result.', array('%original' => $original, '%final' => $final, '%result' => $result)));
+    $this->assertIdentical($result, urldecode($final), format_string('Altered outbound URL %original, expected %final, and got %result.', array('%original' => $original, '%final' => $final, '%result' => $result)));
   }
 
   /**