diff --git a/db/routines/vn/procedures/item_getBalance.sql b/db/routines/vn/procedures/item_getBalance.sql
index 11af7e570..88583cf00 100644
--- a/db/routines/vn/procedures/item_getBalance.sql
+++ b/db/routines/vn/procedures/item_getBalance.sql
@@ -179,7 +179,7 @@ BEGIN
 				LEFT JOIN alertLevel a ON a.id = t.alertLevel;
 
 	ELSE
-		SELECT SUM(`in`) - SUM(`out`) INTO @a
+		SELECT IFNULL(SUM(IFNULL(`in`, 0)) - SUM(IFNULL(`out`, 0)), 0) INTO @a
 			FROM tItemDiary
 			WHERE shipped < vDate;