Bug in Zabbix 2.1.6

diff --git a/frontends/php/api/classes/CHistory.php b/frontends/php/api/classes/CHistory.php
index e1a2292..11f4432 100644
--- a/frontends/php/api/classes/CHistory.php
+++ b/frontends/php/api/classes/CHistory.php
@@ -175,7 +175,7 @@ class CHistory extends CZBXAPI {
                // countOutput
                if (!is_null($options['countOutput'])) {
                        $options['sortfield'] = '';
-                       $sqlParts['select'] = array('count(DISTINCT h.hostid) as rowscount');
+                       $sqlParts['select'] = array('count(DISTINCT h.clock) as rowscount');

                        // groupCount
                        if (!is_null($options['groupCount'])) {