diff --git a/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php b/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
index 2ffc7407..531eec70 100644
--- a/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
+++ b/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
@@ -1017,32 +1017,31 @@ class rcube_kolab_contacts extends rcube_addressbook
      */
     private function _sort_contacts_comp($a, $b)
     {
-        $a_name = $a['name'];
-        $b_name = $b['name'];
+        $a_value = $a[$this->sort_col];
+        $b_value = $b[$this->sort_col];
 
-        if (!$a_name) {
-            $a_name = join(' ', array_filter(array($a['prefix'], $a['firstname'],
-                $a['middlename'], $a['surname'], $a['suffix'])));
-            if (!$a_name) {
-                $a_name = is_array($a['email']) ? $a['email'][0] : $a['email'];
-            }
+        if (!$a_value && $this->sort_col == 'name') {
+            $a_value = join(' ', array_filter(array($a['firstname'], $a['middlename'], $a['surname'])));
         }
-        if (!$b_name) {
-            $b_name = join(' ', array_filter(array($b['prefix'], $b['firstname'],
-                $b['middlename'], $b['surname'], $b['suffix'])));
-            if (!$b_name) {
-                $b_name = is_array($b['email']) ? $b['email'][0] : $b['email'];
-            }
+        if (!$a_value) {
+            $a_value = is_array($a['email']) ? $a['email'][0] : $a['email'];
         }
 
-        // return strcasecmp($a_name, $b_name);
+        if (!$b_value && $this->sort_col == 'name') {
+            $b_value = join(' ', array_filter(array($b['firstname'], $b['middlename'], $b['surname'])));
+        }
+        if (!$b_value) {
+            $b_value = is_array($b['email']) ? $b['email'][0] : $b['email'];
+        }
+
+        // return strcasecmp($a_value, $b_value);
         // make sorting unicode-safe and locale-dependent
-        if ($a_name == $b_name)
+        if ($a_value == $b_value)
             return 0;
 
-        $arr = array($a_name, $b_name);
+        $arr = array($a_value, $b_value);
         sort($arr, SORT_LOCALE_STRING);
-        return $a_name == $arr[0] ? -1 : 1;
+        return $a_value == $arr[0] ? -1 : 1;
     }
 
     /**