diff --git a/tests/test_Configuration.py b/tests/test_Configuration.py
index 4b34e91eb7ff91d0287367fdea9a7c9d96b4d1cb..96f9d05b38c47f8fcb402e9489520302af192b65 100644
--- a/tests/test_Configuration.py
+++ b/tests/test_Configuration.py
@@ -2,6 +2,7 @@ import datetime
 import decimal
 import os
 
+import babel
 import pytest
 
 from . import any_date, relpath
@@ -56,14 +57,17 @@ def test_historical_default_base(ini_filename, expected_currency, use_switch, an
     (decimal.Decimal('12.34'), 'gbp', 'IN', 'eur'),
 ])
 def test_historical_argparsing_success(amount, from_curr, preposition, to_curr, any_date):
+    oxrlib.config.Configuration.TODAY = datetime.date(2017, 1, 1)
+    # This locale's currency should not be used in any test cases above.
+    oxrlib.config.Configuration.LOCALE = babel.core.Locale('en', 'IN')
     arglist = ['historical', any_date.isoformat()]
     arglist.extend(str(s) for s in [amount, from_curr, preposition, to_curr]
                    if s is not None)
     config = config_from(os.devnull, arglist)
+    expect_to_curr = 'INR' if to_curr is None else to_curr.upper()
     assert config.args.amount == amount
     assert config.args.from_currency == from_curr.upper()
-    if to_curr is not None:
-        assert config.args.to_currency == to_curr.upper()
+    assert config.args.to_currency == expect_to_curr
 
 @pytest.mark.parametrize('arglist', [
     ['100'],