diff --git a/core/modules/config/src/Tests/ConfigImportAllTest.php b/core/modules/config/src/Tests/ConfigImportAllTest.php
index 238f948..9024a6a 100644
--- a/core/modules/config/src/Tests/ConfigImportAllTest.php
+++ b/core/modules/config/src/Tests/ConfigImportAllTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\config\Tests;
 
 use Drupal\Core\Config\StorageComparer;
+use Drupal\Core\Url;
 use Drupal\system\Tests\Module\ModuleTestBase;
 
 /**
@@ -127,7 +128,15 @@ public function testInstallUninstall() {
       $this->container->get('config.storage'),
       $this->container->get('config.manager')
     );
-    $this->assertIdentical($storage_comparer->createChangelist()->getChangelist(), $storage_comparer->getEmptyChangelist());
+    $changelist = $storage_comparer->createChangelist()->getChangelist();
+    $this->assertIdentical($changelist, $storage_comparer->getEmptyChangelist());
+    // This helps developers discern what is wrong if the above assertion fails.
+    // If simpletest is in verbose mode this will display diffs of all the
+    // configuration that still needs updating after import.
+    foreach($changelist['update'] as $key => $config_name) {
+      $url = new Url('config.diff', array('source_name' => $config_name));
+      $this->drupalGet($url->toString());
+    }
 
     // Now we have all configuration imported, test all of them for schema
     // conformance. Ensures all imported default configuration is valid when