diff --git a/oslo_serialization/tests/test_msgpackutils.py b/oslo_serialization/tests/test_msgpackutils.py
index f47efb9..55fbae2 100644
--- a/oslo_serialization/tests/test_msgpackutils.py
+++ b/oslo_serialization/tests/test_msgpackutils.py
@@ -15,17 +15,11 @@
 import datetime
 import itertools
 from xmlrpc import client as xmlrpclib
+import zoneinfo
 
 import netaddr
 from oslotest import base as test_base
 
-try:
-    import zoneinfo
-except ImportError:
-    # zoneinfo is available in Python >= 3.9
-    from pytz import timezone
-    zoneinfo = None
-
 from oslo_serialization import msgpackutils
 from oslo_utils import uuidutils
 
@@ -152,30 +146,18 @@ class MsgPackUtilsTest(test_base.BaseTestCase):
 
     def test_datetime_tz_clone(self):
         now = datetime.datetime.now()
-        if zoneinfo:
-            eastern = zoneinfo.ZoneInfo('US/Eastern')
-            e_dt = now.replace(tzinfo=eastern)
-        else:
-            eastern = timezone('US/Eastern')
-            e_dt = eastern.localize(now)
+        eastern = zoneinfo.ZoneInfo('US/Eastern')
+        e_dt = now.replace(tzinfo=eastern)
         e_dt2 = _dumps_loads(e_dt)
         self.assertEqual(e_dt, e_dt2)
         self.assertEqual(e_dt.strftime(_TZ_FMT), e_dt2.strftime(_TZ_FMT))
 
     def test_datetime_tz_different(self):
         now = datetime.datetime.now()
-        if zoneinfo:
-            eastern = zoneinfo.ZoneInfo('US/Eastern')
-            pacific = zoneinfo.ZoneInfo('US/Pacific')
-            now = now.replace(tzinfo=eastern)
-            e_dt = now
-            now = now.replace(tzinfo=pacific)
-            p_dt = now
-        else:
-            eastern = timezone('US/Eastern')
-            pacific = timezone('US/Pacific')
-            e_dt = eastern.localize(now)
-            p_dt = pacific.localize(now)
+        eastern = zoneinfo.ZoneInfo('US/Eastern')
+        pacific = zoneinfo.ZoneInfo('US/Pacific')
+        e_dt = now.replace(tzinfo=eastern)
+        p_dt = now.replace(tzinfo=pacific)
 
         self.assertNotEqual(e_dt, p_dt)
         self.assertNotEqual(e_dt.strftime(_TZ_FMT), p_dt.strftime(_TZ_FMT))