diff --git a/stock/doctype/delivery_note/delivery_note.py b/stock/doctype/delivery_note/delivery_note.py
index e5acd16..00711978 100644
--- a/stock/doctype/delivery_note/delivery_note.py
+++ b/stock/doctype/delivery_note/delivery_note.py
@@ -444,7 +444,7 @@
   def update_pack_nett_weight(self):
       for d in getlist(self.doclist, 'delivery_note_details'):
         if d.item_name:
-          item_wt = sql("select nett_weight from `tabItem` where item_name = '%s'" % (d.item_name))
+          item_wt = sql("select nett_weight from `tabItem` where item_name = %s", (d.item_name))
           d.pack_nett_wt = item_wt and flt(item_wt[0][0])*flt(d.qty) or 0
 
   # ==========================================