diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index a5caaa83..920462c1 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -182,6 +182,12 @@ class calendar extends rcube_plugin
         $this->api->output->add_label('calendar.createfrommail');
       }
     }
+    else if ($args['task'] == 'addressbook') {
+      if ($this->rc->config->get('calendar_contact_birthdays')) {
+        $this->add_hook('contact_update', array($this, 'contact_update'));
+        $this->add_hook('contact_create', array($this, 'contact_update'));
+      }
+    }
 
     // add hooks to display alarms
     $this->add_hook('pending_alarms', array($this, 'pending_alarms'));
@@ -1004,6 +1010,18 @@ class calendar extends rcube_plugin
     $this->rc->output->send();
   }
 
+  /**
+   * Hook triggered when a contact is saved
+   */
+  function contact_update($p)
+  {
+    // clear birthdays calendar cache
+    if (!empty($p['record']['birthday'])) {
+      $cache = $this->rc->get_cache('calendar.birthdays', 'db');
+      $cache->remove();
+    }
+  }
+
   /**
    *
    */
diff --git a/plugins/calendar/drivers/calendar_driver.php b/plugins/calendar/drivers/calendar_driver.php
index 0eedf7fd..af8cb2fc 100644
--- a/plugins/calendar/drivers/calendar_driver.php
+++ b/plugins/calendar/drivers/calendar_driver.php
@@ -444,8 +444,8 @@ abstract class calendar_driver
       $cached = $cache->get($source['id']);
 
       // iterate over (cached) contacts
-      foreach ((array)($cached ?: $abook->list_records()) as $contact) {
-        if (!empty($contact['birthday'])) {
+      foreach (($cached ?: $abook->list_records()) as $contact) {
+        if (is_array($contact) && !empty($contact['birthday'])) {
           try {
             if (is_array($contact['birthday']))
               $contact['birthday'] = reset($contact['birthday']);
@@ -455,7 +455,7 @@ abstract class calendar_driver
             $birthyear = $bday->format('Y');
           }
           catch (Exception $e) {
-            // console('BIRTHDAY PARSE ERROR: ' . $e);
+            console('BIRTHDAY PARSE ERROR: ' . $e);
             continue;
           }