diff --git a/erpnext/controllers/taxes_and_totals.py b/erpnext/controllers/taxes_and_totals.py
index 699e1c6..e968e61 100644
--- a/erpnext/controllers/taxes_and_totals.py
+++ b/erpnext/controllers/taxes_and_totals.py
@@ -29,6 +29,7 @@
 			self.set_item_wise_tax_breakup()
 
 	def _calculate(self):
+		self.validate_conversion_rate()
 		self.calculate_item_values()
 		self.initialize_taxes()
 		self.determine_exclusive_rate()