diff --git a/tests/test_reports_balance.py b/tests/test_reports_balance.py
index 7913156940639c97d059d69c585b24c8fbfa7d4d..5855ba35049e5f59fb3f92d81db24a665282d081 100644
--- a/tests/test_reports_balance.py
+++ b/tests/test_reports_balance.py
@@ -22,6 +22,8 @@ import pytest
 
 from . import testutil
 
+import babel.numbers
+
 from conservancy_beancount.reports import core
 
 DEFAULT_STRINGS = [
@@ -191,6 +193,12 @@ def test_format_sep(sep):
     balance = core.Balance(amounts)
     assert balance.format(sep=sep) == expected
 
+def test_format_none():
+    amounts = testutil.balance_map(BRL=65000)
+    balance = core.Balance(amounts)
+    expected = babel.numbers.format_currency(65000, 'BRL')
+    assert balance.format(None) == expected
+
 @pytest.mark.parametrize('empty', [
     "N/A",
     "Zero",