diff --git a/erpnext/stock/doctype/stock_entry/stock_entry.py b/erpnext/stock/doctype/stock_entry/stock_entry.py
index ebfa7269912..d601dc093b8 100644
--- a/erpnext/stock/doctype/stock_entry/stock_entry.py
+++ b/erpnext/stock/doctype/stock_entry/stock_entry.py
@@ -2648,7 +2648,7 @@ class StockEntry(StockController):
 			self.process_loss_qty = flt(
 				(flt(self.fg_completed_qty) * flt(self.process_loss_percentage)) / 100
 			)
-		elif self.process_loss_qty and not self.process_loss_percentage:
+		elif self.process_loss_qty and self.fg_completed_qty:
 			self.process_loss_percentage = flt(
 				(flt(self.process_loss_qty) / flt(self.fg_completed_qty)) * 100
 			)
diff --git a/erpnext/stock/doctype/stock_entry/test_stock_entry.py b/erpnext/stock/doctype/stock_entry/test_stock_entry.py
index ea231ff466c..79a353ace30 100644
--- a/erpnext/stock/doctype/stock_entry/test_stock_entry.py
+++ b/erpnext/stock/doctype/stock_entry/test_stock_entry.py
@@ -2729,6 +2729,28 @@ class TestStockEntry(FrappeTestCase):
 		# delete naming rule
 		frappe.delete_doc("Document Naming Rule", qc_naming_rule.name)
 
+	def test_process_loss_percentage_resyncs_from_qty(self):
+		# changing fg qty recomputes process_loss_qty
+		se = frappe.new_doc("Stock Entry")
+		se.purpose = "Manufacture"
+		se.fg_completed_qty = 200
+		se.process_loss_qty = 100
+		se.process_loss_percentage = 80
+
+		se.set_process_loss_qty()
+
+		self.assertEqual(se.process_loss_percentage, 50)
+
+	def test_process_loss_qty_derived_from_percentage_when_qty_blank(self):
+		se = frappe.new_doc("Stock Entry")
+		se.purpose = "Manufacture"
+		se.fg_completed_qty = 200
+		se.process_loss_percentage = 25
+
+		se.set_process_loss_qty()
+
+		self.assertEqual(se.process_loss_qty, 50)
+
 
 def make_serialized_item(**args):
 	args = frappe._dict(args)