diff --git a/calendar/inc/class.calendar_so.inc.php b/calendar/inc/class.calendar_so.inc.php
index 5f33d0f83d..cd06bbee61 100644
--- a/calendar/inc/class.calendar_so.inc.php
+++ b/calendar/inc/class.calendar_so.inc.php
@@ -423,7 +423,7 @@ class calendar_so
 			// For deleted history
 			$history_id = $this->cal_table.'.cal_id';
 			// Postgres needs a cast
-			if($this->db->Type == 'postgres') {
+			if($this->db->Type == 'pgsql') {
 				$history_id = "CAST($history_id AS VARCHAR)";
 			}