diff --git a/plugins/serendipity_event_spamblock/ChangeLog b/plugins/serendipity_event_spamblock/ChangeLog
index 6035827a..38f95396 100644
--- a/plugins/serendipity_event_spamblock/ChangeLog
+++ b/plugins/serendipity_event_spamblock/ChangeLog
@@ -1,3 +1,5 @@
+1.89.3: PHP 8 compatibility
+
 1.89.2: Dont refresh timeout when displaying comment preview
 
 1.89.1: Modified sql statement used for htaccess blocking to work in MySQL 5.7.
diff --git a/plugins/serendipity_event_spamblock/serendipity_event_spamblock.php b/plugins/serendipity_event_spamblock/serendipity_event_spamblock.php
index facf0a11..b6ed4678 100644
--- a/plugins/serendipity_event_spamblock/serendipity_event_spamblock.php
+++ b/plugins/serendipity_event_spamblock/serendipity_event_spamblock.php
@@ -25,7 +25,7 @@ class serendipity_event_spamblock extends serendipity_event
             'smarty'      => '2.6.7',
             'php'         => '4.1.0'
         ));
-        $propbag->add('version',       '1.89.2');
+        $propbag->add('version',       '1.89.3');
         $propbag->add('event_hooks',    array(
             'frontend_saveComment' => true,
             'external_plugin'      => true,
@@ -1446,15 +1446,25 @@ class serendipity_event_spamblock extends serendipity_event
                         $eventData['action_more'] .= ' <a class="button_link actions_extra" title="' . PLUGIN_EVENT_SPAMBLOCK_NOT_SPAM . '" href="serendipity_admin.php?serendipity[adminModule]=comments&amp;serendipity[spamNotSpam]=' . $eventData['id'] . $addData . '#' . $clink . '"><span class="icon-ok-circled" aria-hidden="true"></span><span class="visuallyhidden"> ' . PLUGIN_EVENT_SPAMBLOCK_NOT_SPAM . '</span></a>';
                     }
 
+
+                    if (! isset($eventData['action_author'])) {
+                        $eventData['action_author'] = '';
+                    } 
                     $eventData['action_author'] .= ' <a class="button_link" title="' . ($author_is_filtered ? PLUGIN_EVENT_SPAMBLOCK_REMOVE_AUTHOR : PLUGIN_EVENT_SPAMBLOCK_ADD_AUTHOR) . '" href="serendipity_admin.php?serendipity[adminModule]=comments&amp;serendipity[spamBlockAuthor]=' . $eventData['id'] . $addData . $randomString . '#' . $clink . '"><span class="icon-' . ($author_is_filtered ? 'ok-circled' : 'block') .'" aria-hidden="true"></span><span class="visuallyhidden"> ' . ($author_is_filtered ? PLUGIN_EVENT_SPAMBLOCK_REMOVE_AUTHOR : PLUGIN_EVENT_SPAMBLOCK_ADD_AUTHOR) . '</span></a>';
 
                     if (!empty($eventData['url'])) {
                         $url_is_filtered    = $this->checkFilter('urls', $eventData['url']);
+                        if (! isset($eventData['action_url'])) {
+                            $eventData['action_url'] = '';
+                        } 
                         $eventData['action_url']    .= ' <a class="button_link" title="' . ($url_is_filtered ? PLUGIN_EVENT_SPAMBLOCK_REMOVE_URL : PLUGIN_EVENT_SPAMBLOCK_ADD_URL) . '" href="serendipity_admin.php?serendipity[adminModule]=comments&amp;serendipity[spamBlockURL]=' . $eventData['id'] . $addData . $randomString . '#' . $clink . '"><span class="icon-' . ($url_is_filtered ? 'ok-circled' : 'block') .'" aria-hidden="true"></span><span class="visuallyhidden"> ' . ($url_is_filtered ? PLUGIN_EVENT_SPAMBLOCK_REMOVE_URL : PLUGIN_EVENT_SPAMBLOCK_ADD_URL) . '</span></a>';
                     }
 
                     if (!empty($eventData['email'])) {
                         $email_is_filtered    = $this->checkFilter('emails', $eventData['email']);
+                        if (! isset($eventData['action_email'])) {
+                            $eventData['action_email'] = '';
+                        } 
                         $eventData['action_email']    .= ' <a class="button_link" title="' . ($email_is_filtered ? PLUGIN_EVENT_SPAMBLOCK_REMOVE_EMAIL : PLUGIN_EVENT_SPAMBLOCK_ADD_EMAIL) . '" href="serendipity_admin.php?serendipity[adminModule]=comments&amp;serendipity[spamBlockEmail]=' . $eventData['id'] . $addData . $randomString . '#' . $clink . '"><span class="icon-' . ($email_is_filtered ? 'ok-circled' : 'block') .'" aria-hidden="true"></span><span class="visuallyhidden"> ' . ($email_is_filtered ? PLUGIN_EVENT_SPAMBLOCK_REMOVE_EMAIL : PLUGIN_EVENT_SPAMBLOCK_ADD_EMAIL) . '</span></a>';
                     }
                     break;