diff --git a/erpnext/accounts/doctype/cashier_closing/cashier_closing.py b/erpnext/accounts/doctype/cashier_closing/cashier_closing.py
index 6ab94c5c51b..e89f2830223 100644
--- a/erpnext/accounts/doctype/cashier_closing/cashier_closing.py
+++ b/erpnext/accounts/doctype/cashier_closing/cashier_closing.py
@@ -5,6 +5,7 @@
 import frappe
 from frappe import _
 from frappe.model.document import Document
+from frappe.query_builder.functions import Sum
 from frappe.utils import flt
 
 
@@ -43,13 +44,17 @@ class CashierClosing(Document):
 		self.make_calculations()
 
 	def get_outstanding(self):
-		values = frappe.db.sql(
-			"""
-			select sum(outstanding_amount)
-			from `tabSales Invoice`
-			where posting_date=%s and posting_time>=%s and posting_time<=%s and owner=%s
-		""",
-			(self.date, self.from_time, self.time, self.user),
+		si = frappe.qb.DocType("Sales Invoice")
+		values = (
+			frappe.qb.from_(si)
+			.select(Sum(si.outstanding_amount))
+			.where(
+				(si.posting_date == self.date)
+				& (si.posting_time >= self.from_time)
+				& (si.posting_time <= self.time)
+				& (si.owner == self.user)
+			)
+			.run()
 		)
 		self.outstanding_amount = flt(values[0][0] if values else 0)