diff --git a/diff.module b/diff.module
index af446fb..3739d2e 100644
--- a/diff.module
+++ b/diff.module
@@ -4,8 +4,10 @@
  * @file Contains hooks.
  */
 
+use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Routing\RouteMatchInterface;
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Url;
 
 /**
  * Implements hook_form_BASE_FORM_ID_alter().
@@ -123,3 +125,30 @@ function _diff_field_label($entity_type, $field_name) {
   arsort($labels);
   return array_keys($labels);
 }
+
+/**
+ * Returns the url object for diff.
+ *
+ * @param \Drupal\Core\Entity\EntityInterface $entity
+ *   The entity to be compared.
+ * @param $left_vid
+ *   Vid of the left revision.
+ * @param $right_vid
+ *   Vid of the right revision.
+ *
+ * @return \Drupal\Core\Url
+ */
+function diff_route(EntityInterface $entity, $left_vid, $right_vid) {
+  $entity_type_id = $entity->getEntityTypeId();
+  if ($entity->getEntityTypeId() == 'node') {
+    $route_name = 'diff.revisions_diff';
+  }
+  else {
+    $route_name = "entity.$entity_type_id.revisions_diff";
+  }
+  return Url::fromRoute($route_name, [
+    $entity_type_id => $entity->id(),
+    'left_revision' => $left_vid,
+    'right_revision' => $right_vid,
+  ]);
+}
\ No newline at end of file
diff --git a/src/Controller/GenericRevisionController.php b/src/Controller/GenericRevisionController.php
index 7a1fd0c..024381a 100644
--- a/src/Controller/GenericRevisionController.php
+++ b/src/Controller/GenericRevisionController.php
@@ -210,9 +210,9 @@ class GenericRevisionController extends EntityComparisonBase {
           '#account' => $revision->uid->entity,
         );
         $revision_date = $this->date->format($revision->getRevisionCreationTime(), 'short');
-        $url = $entity_type_id != 'node' ? "entity.$entity_type_id.revisions_diff": 'entity.node.revision';
+        $route_name = $entity_type_id != 'node' ? "entity.$entity_type_id.revisions_diff": 'entity.node.revision';
         $revision_link = $this->t($revision_log . '@date', array(
-            '@date' => $this->l($revision_date, Url::fromRoute($url, array(
+            '@date' => $this->l($revision_date, Url::fromRoute($route_name, array(
               $entity_type_id => $revision->id(),
               $entity_type_id . '_revision' => $revision->getRevisionId(),
           ))),
@@ -246,8 +246,6 @@ class GenericRevisionController extends EntityComparisonBase {
    * Returns the navigation row for diff table.
    */
   protected function buildRevisionsNavigation(EntityInterface $entity, $vids, $left_vid, $right_vid) {
-    $entity_type_id = $entity->getEntityTypeId();
-    $entity_id = $entity->id();
     $revisions_count = count($vids);
     $i = 0;
 
@@ -257,17 +255,10 @@ class GenericRevisionController extends EntityComparisonBase {
       $i += 1;
     }
     if ($i != 0) {
-      $url = $entity_type_id != 'node' ? "entity.$entity_type_id.revisions_diff": 'diff.revisions_diff';
       // Second column.
       $row[] = array(
         'data' => $this->l(
-          $this->t('< Previous difference'),
-          Url::fromRoute($url,
-            array(
-              $entity_type_id => $entity_id,
-              'left_revision' => $vids[$i - 1],
-              'right_revision' => $left_vid,
-            ))
+          $this->t('< Previous difference'), diff_route($entity, $vids[$i - 1], $left_vid)
         ),
         'colspan' => 2,
         'class' => 'rev-navigation',
@@ -285,17 +276,10 @@ class GenericRevisionController extends EntityComparisonBase {
       $i += 1;
     }
     if ($revisions_count != $i && $vids[$i - 1] != $vids[$revisions_count - 1]) {
-      $url = $entity_type_id != 'node' ? "entity.$entity_type_id.revisions_diff": 'diff.revisions_diff';
       // Forth column.
       $row[] = array(
         'data' => $this->l(
-          $this->t('Next difference >'),
-          Url::fromRoute($url,
-            array(
-              $entity_type_id => $entity_id,
-              'left_revision' => $right_vid,
-              'right_revision' => $vids[$i],
-            ))
+          $this->t('Next difference >'), diff_route($entity, $right_vid, $vids[$i])
         ),
         'colspan' => 2,
         'class' => 'rev-navigation',