diff --git a/plugins/tasklist/drivers/database/tasklist_database_driver.php b/plugins/tasklist/drivers/database/tasklist_database_driver.php
index 8ad776ab..3c5ad384 100644
--- a/plugins/tasklist/drivers/database/tasklist_database_driver.php
+++ b/plugins/tasklist/drivers/database/tasklist_database_driver.php
@@ -286,7 +286,7 @@ class tasklist_database_driver extends tasklist_driver
 
         if ($filter['mask'] & tasklist::FILTER_MASK_COMPLETE)
             $sql_add .= ' AND complete=1';
-        else  // don't show complete tasks by default
+        else if (empty($filter['since']))  // don't show complete tasks by default
             $sql_add .= ' AND complete<1';
 
         if ($filter['mask'] & tasklist::FILTER_MASK_FLAGGED)
@@ -301,6 +301,10 @@ class tasklist_database_driver extends tasklist_driver
             $sql_add = 'AND (' . join(' OR ', $sql_query) . ')';
         }
 
+        if ($filter['since'] && is_numeric($filter['since'])) {
+            $sql_add .= ' AND changed >= ' . $this->rc->db->quote(date('Y-m-d H:i:s', $filter['since']));
+        }
+
         $tasks = array();
         if (!empty($list_ids)) {
             $result = $this->rc->db->query(sprintf(
diff --git a/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php b/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php
index 6e41fd75..18a45770 100644
--- a/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php
+++ b/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php
@@ -372,7 +372,7 @@ class tasklist_kolab_driver extends tasklist_driver
         $query = array();
         if ($filter['mask'] & tasklist::FILTER_MASK_COMPLETE)
             $query[] = array('tags','~','x-complete');
-        else
+        else if (empty($filter['since']))
             $query[] = array('tags','!~','x-complete');
 
         // full text search (only works with cache enabled)
@@ -383,6 +383,10 @@ class tasklist_kolab_driver extends tasklist_driver
             }
         }
 
+        if ($filter['since']) {
+            $query[] = array('changed', '>=', $filter['since']);
+        }
+
         foreach ($lists as $list_id) {
             $folder = $this->folders[$list_id];
             foreach ((array)$folder->select($query) as $record) {
diff --git a/plugins/tasklist/tasklist.js b/plugins/tasklist/tasklist.js
index 19db0fe9..631494c6 100644
--- a/plugins/tasklist/tasklist.js
+++ b/plugins/tasklist/tasklist.js
@@ -132,6 +132,7 @@ function rcube_tasklist_ui(settings)
         rcmail.addEventListener('plugin.destroy_tasklist', destroy_list);
         rcmail.addEventListener('plugin.reload_data', function(){ list_tasks(null); });
         rcmail.addEventListener('plugin.unlock_saving', unlock_saving);
+        rcmail.addEventListener('requestrefresh', before_refresh);
 
         // start loading tasks
         fetch_counts();
@@ -438,6 +439,19 @@ function rcube_tasklist_ui(settings)
         loadstate.lists = active_lists();
     }
 
+    /**
+     * Modify query parameters for refresh requests
+     */
+    function before_refresh(query)
+    {
+        query.filter = filtermask == FILTER_MASK_COMPLETE ? FILTER_MASK_COMPLETE : FILTER_MASK_ALL;
+        query.lists = active_lists().join(',');
+        if (search_query)
+            query.q = search_query;
+
+        return query;
+    }
+
     /**
      * Callback if task data from server is ready
      */
diff --git a/plugins/tasklist/tasklist.php b/plugins/tasklist/tasklist.php
index 9d5544cd..e6b5d1cd 100644
--- a/plugins/tasklist/tasklist.php
+++ b/plugins/tasklist/tasklist.php
@@ -90,6 +90,7 @@ class tasklist extends rcube_plugin
             $this->register_action('mail2task', array($this, 'mail_message2task'));
             $this->register_action('get-attachment', array($this, 'attachment_get'));
             $this->register_action('upload', array($this, 'attachment_upload'));
+            $this->add_hook('refresh', array($this, 'refresh'));
 
             $this->collapsed_tasks = array_filter(explode(',', $this->rc->config->get('tasklist_collapsed_tasks', '')));
         }
@@ -540,8 +541,17 @@ class tasklist extends rcube_plugin
 
         }
 */
+        $data = $this->tasks_data($this->driver->list_tasks($filter, $lists), $f, $tags);
+        $this->rc->output->command('plugin.data_ready', array('filter' => $f, 'lists' => $lists, 'search' => $search, 'data' => $data, 'tags' => array_values(array_unique($tags))));
+    }
+
+    /**
+     * Prepare and sort the given task records to be sent to the client
+     */
+    private function tasks_data($records, $f, &$tags)
+    {
         $data = $tags = $this->task_tree = $this->task_titles = array();
-        foreach ($this->driver->list_tasks($filter, $lists) as $rec) {
+        foreach ($records as $rec) {
             if ($rec['parent_id']) {
                 $this->task_tree[$rec['id']] = $rec['parent_id'];
             }
@@ -558,7 +568,7 @@ class tasklist extends rcube_plugin
         array_walk($data, array($this, 'task_walk_tree'));
         usort($data, array($this, 'task_sort_cmp'));
 
-        $this->rc->output->command('plugin.data_ready', array('filter' => $f, 'lists' => $lists, 'search' => $search, 'data' => $data, 'tags' => array_values(array_unique($tags))));
+        return $data;
     }
 
     /**
@@ -724,6 +734,28 @@ class tasklist extends rcube_plugin
         exit;
     }
 
+    /**
+     * Handler for keep-alive requests
+     * This will check for updated data in active lists and sync them to the client
+     */
+    public function refresh($attr)
+    {
+        $filter = array(
+            'since'  => $attr['last'],
+            'search' => get_input_value('q', RCUBE_INPUT_GPC),
+            'mask'   => intval(get_input_value('filter', RCUBE_INPUT_GPC)) & self::FILTER_MASK_COMPLETE,
+        );
+        $lists = get_input_value('lists', RCUBE_INPUT_GPC);;
+
+        $updates = $this->driver->list_tasks($filter, $lists);
+        if (!empty($updates)) {
+            $this->rc->output->command('plugin.refresh_task', $this->tasks_data($updates, 255, $tags));
+
+            // update counts
+            $counts = $this->driver->count_tasks($lists);
+            $this->rc->output->command('plugin.update_counts', $counts);
+        }
+    }
 
     /**
      * Handler for pending_alarms plugin hook triggered by the calendar module on keep-alive requests.