diff --git a/erpnext/accounts/doctype/sales_invoice/sales_invoice.py b/erpnext/accounts/doctype/sales_invoice/sales_invoice.py
index 6e039b4b34f..97871ba7d6f 100644
--- a/erpnext/accounts/doctype/sales_invoice/sales_invoice.py
+++ b/erpnext/accounts/doctype/sales_invoice/sales_invoice.py
@@ -1083,13 +1083,16 @@ class SalesInvoice(SellingController):
 					timesheet.billing_amount = ts_doc.total_billable_amount
 
 	def update_timesheet_billing_for_project(self):
-		if not self.timesheets and self.project:
-			self.add_timesheet_data()
-		else:
+		if self.timesheets:
 			self.calculate_billing_amount_for_timesheet()
 
-	@frappe.whitelist()
+	@frappe.whitelist(methods=["PUT"])
 	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 da042f36aef..39140b335c9 100644
--- a/erpnext/projects/doctype/timesheet/test_timesheet.py
+++ b/erpnext/projects/doctype/timesheet/test_timesheet.py
@@ -62,6 +62,7 @@ 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)