diff -u b/src/EntityComparisonBase.php b/src/EntityComparisonBase.php
--- b/src/EntityComparisonBase.php
+++ b/src/EntityComparisonBase.php
@@ -16,6 +16,7 @@
 use Drupal\Core\Datetime\DateFormatter;
 use Drupal\Component\Utility\Xss;
 use Drupal\Core\Mail\MailFormatHelper;
+use Drupal\Component\Utility\SafeMarkup;
 
 /**
  * Builds an array of data out of entity fields.
@@ -82,7 +83,7 @@
     $this->fieldTypeDefinitions = $plugin_manager->getDefinitions();
     $this->config = $this->config('diff.settings');
     $this->pluginsConfig = $this->config('diff.plugins');
-    $this->nonBreakingSpace = t('&nbsp');
+    $this->nonBreakingSpace = SafeMarkup::format('&nbsp', array());
     $this->entityParser = $entityParser;
   }