diff --git a/phpgwapi/inc/class.historylog.inc.php b/phpgwapi/inc/class.historylog.inc.php
index 99e2aea8bf..425a1cb69c 100644
--- a/phpgwapi/inc/class.historylog.inc.php
+++ b/phpgwapi/inc/class.historylog.inc.php
@@ -153,7 +153,7 @@ class historylog
 	 */
 	function search($filter,$order='history_id',$sort='DESC')
 	{
-		if (!is_array($filter)) $filter = (int)$filter ? array('history_record_id' => $filter) : array();
+		if (!is_array($filter)) $filter = is_numeric($filter) ? array('history_record_id' => $filter) : array();
 
 		if (!$_orderby || !preg_match('/^[a-z0-9_]+$/i',$_orderby) || !preg_match('/^(asc|desc)?$/i',$sort))
 		{
@@ -173,6 +173,9 @@ class historylog
 		}
 		if (!isset($filter['history_appname'])) $filter['history_appname'] = $this->appname;
 
+		// do not try to read all history entries of an app
+		if (!$filter['history_record_id']) return array();
+
 		$rows = array();
 		foreach($this->db->select(self::TABLE,'*',$filter,__LINE__,__FILE__,false,$orderby) as $row)
 		{
@@ -274,7 +277,10 @@ class historylog
 	 */
 	function return_array($filter_out,$only_show,$_orderby,$sort, $record_id)
 	{
-
+		if (!is_numeric($record_id))
+		{
+			return array();
+		}
 		if (!$_orderby || !preg_match('/^[a-z0-9_]+$/i',$_orderby) || !preg_match('/^(asc|desc)?$/i',$sort))
 		{
 			$orderby = 'ORDER BY history_timestamp,history_id';