diff --git a/erpnext/accounts/doctype/accounts_settings/accounts_settings.py b/erpnext/accounts/doctype/accounts_settings/accounts_settings.py
index 7280322..f0890dd 100644
--- a/erpnext/accounts/doctype/accounts_settings/accounts_settings.py
+++ b/erpnext/accounts/doctype/accounts_settings/accounts_settings.py
@@ -14,9 +14,6 @@
 		frappe.db.set_default("auto_accounting_for_stock", self.auto_accounting_for_stock)
 
 		if cint(self.auto_accounting_for_stock):
-			if cint(frappe.db.get_value("Stock Settings", None, "allow_negative_stock")):
-				frappe.throw(_("Negative stock is not allowed in case of Perpetual Inventory, please disable it from Stock Settings"))
-
 			# set default perpetual account in company
 			for company in frappe.db.sql("select name from tabCompany"):
 				frappe.get_doc("Company", company[0]).save()
diff --git a/erpnext/controllers/buying_controller.py b/erpnext/controllers/buying_controller.py
index 66d5792..cf57658 100644
--- a/erpnext/controllers/buying_controller.py
+++ b/erpnext/controllers/buying_controller.py
@@ -277,6 +277,9 @@
 					"qty": -1 * required_qty,
 					"serial_no": rm.serial_no
 				})
+				if not item_rate:
+					from erpnext.controllers.stock_controller import get_valuation_rate
+					item_rate = get_valuation_rate(bom_item.item_code, self.supplier_warehouse)
 				rm.rate = item_rate or bom_item.rate
 			else:
 				rm.rate = bom_item.rate
diff --git a/erpnext/controllers/stock_controller.py b/erpnext/controllers/stock_controller.py
index ad553d8..a72a3d0 100644
--- a/erpnext/controllers/stock_controller.py
+++ b/erpnext/controllers/stock_controller.py
@@ -30,7 +30,7 @@
 	def get_gl_entries(self, warehouse_account=None, default_expense_account=None,
 			default_cost_center=None, allow_negative_stock=False):
 
-		block_negative_stock(allow_negative_stock)
+		# block_negative_stock(allow_negative_stock)
 
 		if not warehouse_account:
 			warehouse_account = get_warehouse_account()
@@ -319,4 +319,7 @@
 	if not valuation_rate:
 		valuation_rate = frappe.db.get_value("Item Price", {"item_code": item_code, "buying": 1}, "price_list_rate")
 
+	if not valuation_rate:
+		frappe.throw(_("Purchase rate for item: {0} not found, which is required to book accounting entry. Please mention item price against a buying price list.").format(item_code))
+
 	return valuation_rate
diff --git a/erpnext/stock/doctype/purchase_receipt/purchase_receipt.py b/erpnext/stock/doctype/purchase_receipt/purchase_receipt.py
index fc35222..ed4257f 100644
--- a/erpnext/stock/doctype/purchase_receipt/purchase_receipt.py
+++ b/erpnext/stock/doctype/purchase_receipt/purchase_receipt.py
@@ -287,7 +287,7 @@
 		from erpnext.accounts.general_ledger import process_gl_map
 		from erpnext.controllers.stock_controller import block_negative_stock
 
-		block_negative_stock(allow_negative_stock)
+		# block_negative_stock(allow_negative_stock)
 
 		stock_rbnb = self.get_company_default("stock_received_but_not_billed")
 		expenses_included_in_valuation = self.get_company_default("expenses_included_in_valuation")
diff --git a/erpnext/stock/stock_ledger.py b/erpnext/stock/stock_ledger.py
index a2614d7..2956170 100644
--- a/erpnext/stock/stock_ledger.py
+++ b/erpnext/stock/stock_ledger.py
@@ -269,7 +269,7 @@
 	elif not valuation_rate:
 		valuation_rate = get_valuation_rate(sle.item_code, sle.warehouse)
 
-	return abs(valuation_rate)
+	return abs(flt(valuation_rate))
 
 def get_fifo_values(qty_after_transaction, sle, stock_queue):
 	incoming_rate = flt(sle.incoming_rate)