diff -u b/src/Form/RevisionOverviewForm.php b/src/Form/RevisionOverviewForm.php
--- b/src/Form/RevisionOverviewForm.php
+++ b/src/Form/RevisionOverviewForm.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\diff\Form;
 
+use Drupal\Component\Utility\Xss;
 use Drupal\Core\Language\LanguageManagerInterface;
 use Drupal\diff\DiffEntityComparison;
 use Drupal\diff\DiffLayoutManager;
@@ -154,7 +155,6 @@
 
     $table_header = array(
       'revision' => $this->t('Revision'),
-      'summary' => $this->t('Summary'),
       'operations' => $this->t('Operations'),
     );
 
@@ -214,12 +214,12 @@
                 '#context' => [
                   'date' => $link,
                   'username' => $this->renderer->renderPlain($username),
+                  'message' => [
+                    '#markup' => $this->entityComparison->getRevisionDescription($revision, isset($vids[$key + 1]) ? $vids[$key + 1] : $vids[$key]),
+                    '#allowed_tags' => Xss::getHtmlTagList()
+                  ],
                 ],
               ),
-              'summary' => [
-                '#type' => 'markup',
-                '#markup' => $this->entityComparison->getRevisionDescription($revision, isset($vids[$key + 1]) ? $vids[$key + 1] : $vids[$key]),
-              ],
             );
             // Allow comparisons only if there are 2 or more revisions.
             if ($revision_count > 1) {
@@ -282,12 +282,12 @@
                 '#context' => [
                   'date' => $link,
                   'username' => $this->renderer->renderPlain($username),
+                  'message' => [
+                    '#markup' => $this->entityComparison->getRevisionDescription($revision, isset($vids[$key + 1]) ? $vids[$key + 1] : $vids[$key]),
+                    '#allowed_tags' => Xss::getHtmlTagList()
+                  ],
                 ],
               ),
-              'summary' => [
-                '#type' => 'markup',
-                '#markup' => $this->entityComparison->getRevisionDescription($revision, isset($vids[$key + 1]) ? $vids[$key + 1] : $vids[$key]),
-              ],
               'select_column_one' => array(
                 '#type' => 'radio',
                 '#title_display' => 'invisible',
only in patch2:
unchanged:
--- a/src/Tests/DiffRevisionTest.php
+++ b/src/Tests/DiffRevisionTest.php
@@ -72,7 +72,7 @@ class DiffRevisionTest extends DiffTestBase {
     // Make sure only two revisions available.
     $this->assertEqual(count($rows), 2);
     // Assert the revision summary.
-    $this->assertText('Revision 2 comment');
+    $this->assertUniqueText('Revision 2 comment');
     $this->assertText('No changes.');
 
     // Compare the revisions in standard mode.