diff --git a/erpnext/selling/report/customers_not_buying_since_long_time/customers_not_buying_since_long_time.py b/erpnext/selling/report/customers_not_buying_since_long_time/customers_not_buying_since_long_time.py
index 2b2c550..de4c655 100644
--- a/erpnext/selling/report/customers_not_buying_since_long_time/customers_not_buying_since_long_time.py
+++ b/erpnext/selling/report/customers_not_buying_since_long_time/customers_not_buying_since_long_time.py
@@ -43,8 +43,8 @@
 
 def get_last_so_amt(customer):
 	res =  frappe.db.sql("""select base_net_total from `tabSales Order`
-		where customer ='%(customer)s' and docstatus = 1 order by transaction_date desc
-		limit 1""" % {'customer': frappe.db.escape(customer)})
+		where customer = %s and docstatus = 1 order by transaction_date desc
+		limit 1""", customer)
 
 	return res and res[0][0] or 0