diff --git a/erpnext/accounts/doctype/sales_invoice/sales_invoice.py b/erpnext/accounts/doctype/sales_invoice/sales_invoice.py
index 97871ba7d6f..6e039b4b34f 100644
--- a/erpnext/accounts/doctype/sales_invoice/sales_invoice.py
+++ b/erpnext/accounts/doctype/sales_invoice/sales_invoice.py
@@ -1083,16 +1083,13 @@ class SalesInvoice(SellingController):
 					timesheet.billing_amount = ts_doc.total_billable_amount
 
 	def update_timesheet_billing_for_project(self):
-		if self.timesheets:
+		if not self.timesheets and self.project:
+			self.add_timesheet_data()
+		else:
 			self.calculate_billing_amount_for_timesheet()
 
-	@frappe.whitelist(methods=["PUT"])
+	@frappe.whitelist()
 	def add_timesheet_data(self):
-		if not self.timesheets and self.project:
-			self._add_timesheet_data()
-			self.save()
-
-	def _add_timesheet_data(self):
 		self.set("timesheets", [])
 		if self.project:
 			for data in get_projectwise_timesheet_data(self.project):
diff --git a/erpnext/projects/doctype/timesheet/test_timesheet.py b/erpnext/projects/doctype/timesheet/test_timesheet.py
index 39140b335c9..da042f36aef 100644
--- a/erpnext/projects/doctype/timesheet/test_timesheet.py
+++ b/erpnext/projects/doctype/timesheet/test_timesheet.py
@@ -62,7 +62,6 @@ class TestTimesheet(unittest.TestCase):
 		)
 		sales_invoice = create_sales_invoice(do_not_save=True)
 		sales_invoice.project = project
-		sales_invoice._add_timesheet_data()
 		sales_invoice.submit()
 
 		ts = frappe.get_doc("Timesheet", timesheet.name)