diff -u b/core/modules/config/src/Tests/SchemaCheckTestTrait.php b/core/modules/config/src/Tests/SchemaCheckTestTrait.php
--- b/core/modules/config/src/Tests/SchemaCheckTestTrait.php
+++ b/core/modules/config/src/Tests/SchemaCheckTestTrait.php
@@ -9,6 +9,7 @@
 
 use Drupal\Core\Config\TypedConfigManagerInterface;
 use Drupal\Core\Config\Schema\SchemaCheckTrait;
+use Drupal\Component\Utility\SafeMarkup;
 
 /**
  * Provides a class for checking configuration schema.
@@ -32,19 +33,19 @@
     if ($errors === FALSE) {
       // @todo Since the use of this trait is under TestBase, it works.
       //   Can be fixed as part of https://www.drupal.org/node/2260053.
-      $this->fail("No schema for $config_name.");
+      $this->fail(SafeMarkup::format('No schema for @config_name', array('@config_name' => $config_name)));
       return;
     }
     elseif ($errors === TRUE) {
       // @todo Since the use of this trait is under TestBase, it works.
       //   Can be fixed as part of https://www.drupal.org/node/2260053.
-      $this->pass("Schema found for $config_name.");
+      $this->pass(SafeMarkup::format('Schema found for @config_name and values comply with schema.', array('@config_name' => $config_name)));
     }
     else {
       foreach ($errors as $key => $error) {
         // @todo Since the use of this trait is under TestBase, it works.
         //   Can be fixed as part of https://www.drupal.org/node/2260053.
-        $this->fail("Schema key $key failed with: $error.");
+        $this->fail(SafeMarkup::format('Schema key @key failed with: @error', array('@key' => $key, '@error' => $error)));
       }
     }
   }
diff -u b/core/modules/field/src/Tests/FieldImportDeleteTest.php b/core/modules/field/src/Tests/FieldImportDeleteTest.php
--- b/core/modules/field/src/Tests/FieldImportDeleteTest.php
+++ b/core/modules/field/src/Tests/FieldImportDeleteTest.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\field\Tests;
 
+use Drupal\Component\Utility\SafeMarkup;
 use Drupal\field\Entity\FieldConfig;
 use Drupal\field\Entity\FieldStorageConfig;
 
@@ -64,11 +65,11 @@
     $active = $this->container->get('config.storage');
     $staging = $this->container->get('config.storage.staging');
     $this->copyConfig($active, $staging);
-    $this->assertTrue($staging->delete($field_storage_config_name), "Deleted field storage: $field_storage_config_name");
-    $this->assertTrue($staging->delete($field_storage_config_name_2), "Deleted field storage: $field_storage_config_name_2");
-    $this->assertTrue($staging->delete($field_config_name), "Deleted field: $field_config_name");
-    $this->assertTrue($staging->delete($field_config_name_2a), "Deleted field: $field_config_name_2a");
-    $this->assertTrue($staging->delete($field_config_name_2b), "Deleted field: $field_config_name_2b");
+    $this->assertTrue($staging->delete($field_storage_config_name), SafeMarkup::format('Deleted field storage: @field_storage', array('@field_storage' => $field_storage_config_name)));
+    $this->assertTrue($staging->delete($field_storage_config_name_2), SafeMarkup::format('Deleted field storage: @field_storage', array('@field_storage' => $field_storage_config_name_2)));
+    $this->assertTrue($staging->delete($field_config_name), SafeMarkup::format('Deleted field: @field', array('@field' => $field_config_name)));
+    $this->assertTrue($staging->delete($field_config_name_2a), SafeMarkup::format('Deleted field: @field', array('@field' => $field_config_name_2a)));
+    $this->assertTrue($staging->delete($field_config_name_2b), SafeMarkup::format('Deleted field: @field', array('@field' => $field_config_name_2b)));
 
     $deletes = $this->configImporter()->getUnprocessedConfiguration('delete');
     $this->assertEqual(count($deletes), 5, 'Importing configuration will delete 3 fields and 2 field storages.');