diff --git a/erpnext/projects/doctype/project/project.py b/erpnext/projects/doctype/project/project.py
index a7446a8..918da46 100644
--- a/erpnext/projects/doctype/project/project.py
+++ b/erpnext/projects/doctype/project/project.py
@@ -178,8 +178,8 @@
 		self.total_purchase_cost = total_purchase_cost and total_purchase_cost[0][0] or 0
 		
 	def update_sales_costing(self):
-		total_sales_cost = frappe.db.sql("""select sum(base_net_amount)
-			from `tabSales Order Item` where project = %s and docstatus=1""", self.name)
+		total_sales_cost = frappe.db.sql("""select sum(total)
+			from `tabSales Order` where project = %s and docstatus=1""", self.name)
 
 		self.total_sales_cost = total_sales_cost and total_sales_cost[0][0] or 0