diff --git a/erpnext/accounts/doctype/process_period_closing_voucher/process_period_closing_voucher.py b/erpnext/accounts/doctype/process_period_closing_voucher/process_period_closing_voucher.py
index 801c895f37c..24c8c92c7e8 100644
--- a/erpnext/accounts/doctype/process_period_closing_voucher/process_period_closing_voucher.py
+++ b/erpnext/accounts/doctype/process_period_closing_voucher/process_period_closing_voucher.py
@@ -553,7 +553,8 @@ def process_individual_date(docname: str, date, report_type, parentfield):
 		Sum(gle.credit).as_("credit"),
 		Sum(gle.debit_in_account_currency).as_("debit_in_account_currency"),
 		Sum(gle.credit_in_account_currency).as_("credit_in_account_currency"),
-		gle.account_currency,
+		# account_currency is constant per grouped account -> Max() keeps the GROUP BY postgres-valid
+		Max(gle.account_currency).as_("account_currency"),
 	).where(
 		(gle.company.eq(company))
 		& (gle.is_cancelled.eq(0))