diff --git a/buying/doctype/purchase_common/purchase_common.js b/buying/doctype/purchase_common/purchase_common.js
index f0f3867..1bb64e5 100644
--- a/buying/doctype/purchase_common/purchase_common.js
+++ b/buying/doctype/purchase_common/purchase_common.js
@@ -224,8 +224,9 @@
 		var me = this;
 		
 		if(this.frm.doc.doctype != "Purchase Invoice") {
-			wn.meta.docfield_map[this.tname]["rate"] = $.extend({}, 
-				wn.meta.docfield_map[this.tname]["purchase_rate"]);
+			// hack!
+			wn.meta.docfield_copy[this.tname][this.frm.doc.name]["rate"] = $.extend({}, 
+				wn.meta.docfield_copy[this.tname][this.frm.doc.name]["purchase_rate"]);
 		}
 		
 		$.each(this.frm.item_doclist, function(i, item) {
@@ -241,6 +242,7 @@
 			me._set_in_company_currency(item, "import_rate", "rate");
 			me._set_in_company_currency(item, "import_amount", "amount");
 		});
+		
 	},
 	
 	calculate_net_total: function() {
@@ -299,7 +301,8 @@
 		// except in purchase invoice, rate field is purchase_rate		
 		// reset fieldname of rate
 		if(this.frm.doc.doctype != "Purchase Invoice") {
-			delete wn.meta.docfield_map[this.tname]["rate"];
+			// clear hack
+			delete wn.meta.docfield_copy[this.tname][this.frm.doc.name]["rate"];
 			
 			$.each(this.frm.item_doclist, function(i, item) {
 				item.purchase_rate = item.rate;
diff --git a/utilities/transaction_base.py b/utilities/transaction_base.py
index 5b716fc..3571215 100644
--- a/utilities/transaction_base.py
+++ b/utilities/transaction_base.py
@@ -310,7 +310,8 @@
 		
 		# round it
 		args.conversion_rate = flt(args.conversion_rate, 
-			get_field_precision(meta.get_field("conversion_rate"), args))
+			get_field_precision(meta.get_field("conversion_rate"), 
+				webnotes._dict({"fields": args})))
 	
 	# validate price list conversion rate
 	if meta.get_field("price_list_currency") and args.price_list_name and \
@@ -320,6 +321,7 @@
 		
 		# round it
 		args.plc_conversion_rate = flt(args.plc_conversion_rate, 
-			get_field_precision(meta.get_field("plc_conversion_rate"), args))	
+			get_field_precision(meta.get_field("plc_conversion_rate"), 
+				webnotes._dict({"fields": args})))
 	
 	
\ No newline at end of file