diff --git a/erpnext/manufacturing/doctype/bom/bom.py b/erpnext/manufacturing/doctype/bom/bom.py
index 25843fd7ae4..93ee04d0526 100644
--- a/erpnext/manufacturing/doctype/bom/bom.py
+++ b/erpnext/manufacturing/doctype/bom/bom.py
@@ -529,6 +529,7 @@ class BOM(WebsiteGenerator):
 		doc.set_status(save=True)
 
 	def set_fg_cost_allocation(self):
+		self.cost_allocation_per = flt(self.cost_allocation_per)
 		total_secondary_items_per = 0
 		own_cost = 0
 		for item in self.secondary_items: