diff --git a/erpnext/payroll/doctype/salary_slip/salary_slip.py b/erpnext/payroll/doctype/salary_slip/salary_slip.py
index 7e1fb0616d0..a25e94d122b 100644
--- a/erpnext/payroll/doctype/salary_slip/salary_slip.py
+++ b/erpnext/payroll/doctype/salary_slip/salary_slip.py
@@ -646,10 +646,13 @@ class SalarySlip(TransactionBase):
 				continue
 
 			if (
-				(not d.additional_salary
-				and (not additional_salary or additional_salary.overwrite))
-				or (additional_salary
-				and additional_salary.name == d.additional_salary)
+				(
+					not d.additional_salary
+					and (not additional_salary or additional_salary.overwrite)
+				) or (
+					additional_salary
+					and additional_salary.name == d.additional_salary
+				)
 			):
 				component_row = d
 				break
@@ -680,8 +683,13 @@ class SalarySlip(TransactionBase):
 			component_row.set('abbr', abbr)
 
 		if additional_salary:
-			component_row.default_amount = 0
-			component_row.additional_amount = amount
+			if additional_salary.overwrite:
+				component_row.additional_amount = flt(flt(amount) - flt(component_row.get("default_amount", 0)),
+					component_row.precision("additional_amount"))
+			else:
+				component_row.default_amount = 0
+				component_row.additional_amount = amount
+
 			component_row.additional_salary = additional_salary.name
 			component_row.deduct_full_tax_on_selected_payroll_date = \
 				additional_salary.deduct_full_tax_on_selected_payroll_date