diff --git a/erpnext/controllers/buying_controller.py b/erpnext/controllers/buying_controller.py
index 85c14494181..b279d940512 100644
--- a/erpnext/controllers/buying_controller.py
+++ b/erpnext/controllers/buying_controller.py
@@ -195,7 +195,7 @@ class BuyingController(StockController):
 
 				self.round_floats_in(item)
 
-				item.conversion_factor = get_conversion_factor(item.item_code, item.uom).get("conversion_factor")
+				item.conversion_factor = get_conversion_factor(item.item_code, item.uom).get("conversion_factor") or 1.0
 
 				qty_in_stock_uom = flt(item.qty * item.conversion_factor)
 				rm_supp_cost = flt(item.rm_supp_cost) if self.doctype=="Purchase Receipt" else 0.0