diff --git a/CHANGES.txt b/CHANGES.txt
index 0b319fb5..8b00cefd 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,13 @@
+1.0 (unreleased)
+================
+
+- Move 'substanced.locking.now' to 'substanced.util.now', and rework to avoid
+  warning spew for 'datetime.datetime.utcnow'.
+
+- Suppress other warning spew from upstreams in newer Python versions
+  ('chameleon' / AST, 'pkg_resources', etc.)
+
+
 1.0b1 (2024-11-27)
 ==================
 
@@ -26,7 +36,7 @@
 - Override ``serialize`` for ``ReferenceIdSchemaNode``.
   See https://github.com/Pylons/substanced/pull/311
 
-- Get all tests running under ``py.test`` against head of Pyramid's 
+- Get all tests running under ``py.test`` against head of Pyramid's
   ``1.10`` branch.  See https://github.com/Pylons/substanced/pull/309
 
 - Add support for Python 3.6 and 3.7; drop support for Python 3.4.
@@ -111,7 +121,7 @@
   the change.
 
 - Removed Python 2.6 compatibility shim ``substanced._compat.total_ordering``.
-  
+
 1.0a1 (2015-04-17)
 ==================
 
diff --git a/demos/blog/blog/views/retail.py b/demos/blog/blog/views/retail.py
index e8d52522..f25093f8 100644
--- a/demos/blog/blog/views/retail.py
+++ b/demos/blog/blog/views/retail.py
@@ -7,7 +7,10 @@
 from pyramid.decorator import reify
 from pyramid.httpexceptions import HTTPFound
 from pyramid.url import resource_url
-from substanced.util import find_catalog
+from substanced.util import (
+    find_catalog,
+    now,
+)
 from pyramid.view import (
     view_config,
     view_defaults,
@@ -122,11 +125,6 @@ def __init__(self, context, request):
         self.context = context
         self.request = request
 
-    def _nowtz(self):
-        now = datetime.datetime.utcnow() # naive
-        y, mo, d, h, mi, s = now.timetuple()[:6]
-        return datetime.datetime(y, mo, d, h, mi, s, tzinfo=pytz.utc)
-
     def _get_feed_info(self):
         context = self.context
         request = self.request
@@ -160,7 +158,7 @@ def _add_updated_strings(updated, info):
                 
         blogentries.sort(key=lambda x: x[0].isoformat())
         blogentries = [entry[1] for entry in reversed(blogentries)][:15]
-        updated = blogentries and blogentries[0]['pubdate'] or self._nowtz()
+        updated = blogentries and blogentries[0]['pubdate'] or now()
         _add_updated_strings(updated, feed)
         
         return feed, blogentries
diff --git a/pytest.ini b/pytest.ini
index 8e2c1f9a..e104f6c5 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -3,5 +3,9 @@ addopts = -l --strict
 norecursedirs = lib include .tox .git
 python_files = test_*.py tests.py
 filterwarnings =
+     ignore::DeprecationWarning:chameleon
      ignore::DeprecationWarning:pkg_resources
+     ignore:.*pkg_resources:DeprecationWarning
+     ignore:.*Attribute . is deprecated:DeprecationWarning
+     ignore::DeprecationWarning:webob
      ignore::DeprecationWarning:zodburi
diff --git a/substanced/audit/tests/test_views.py b/substanced/audit/tests/test_views.py
index fdaa864d..e780e4a5 100644
--- a/substanced/audit/tests/test_views.py
+++ b/substanced/audit/tests/test_views.py
@@ -1,4 +1,6 @@
+import datetime
 import unittest
+
 from pyramid import testing
 
 class Test_AuditLogEventStreamView(unittest.TestCase):
@@ -93,11 +95,10 @@ def test_auditstream_sse_with_last_event_id_and_oids(self):
         self.assertEqual(list(auditlog.oids), [3])
 
     def test_auditing(self):
-        import pytz
         context = testing.DummyResource()
         request = testing.DummyRequest()
         request.user = testing.DummyResource()
-        request.user.timezone = pytz.timezone('UTC')
+        request.user.timezone = datetime.timezone.utc
         inst = self._makeOne(context, request)
         inst.get_auditlog = lambda c: DummyAuditLog()
         result = inst.auditing()
diff --git a/substanced/content/test_it.py b/substanced/content/test_it.py
index 2368712b..f11923ce 100644
--- a/substanced/content/test_it.py
+++ b/substanced/content/test_it.py
@@ -24,7 +24,6 @@ def test_add_with_meta(self):
     def test_create(self):
         registry = DummyRegistry()
         inst = self._makeOne(registry)
-        inst._utcnow = lambda *a: 1
         content = testing.DummyResource()
         inst.content_types['dummy'] = lambda a: content
         inst.meta['dummy'] = {}
@@ -34,7 +33,6 @@ def test_create(self):
     def test_create_with_oid(self):
         registry = DummyRegistry()
         inst = self._makeOne(registry)
-        inst._utcnow = lambda *a: 1
         content = testing.DummyResource()
         inst.content_types['dummy'] = lambda a: content
         inst.meta['dummy'] = {}
diff --git a/substanced/locking/__init__.py b/substanced/locking/__init__.py
index ae57edba..73bd96da 100644
--- a/substanced/locking/__init__.py
+++ b/substanced/locking/__init__.py
@@ -7,7 +7,6 @@
 
 import datetime
 import uuid
-import pytz
 
 from zope.interface import implementer
 
@@ -43,6 +42,7 @@
     find_objectmap,
     find_service,
     get_oid,
+    now,
     )
 from substanced.schema import Schema
 
@@ -69,9 +69,6 @@ class UnlockError(LockingError):
     or ``None`` if there was no lock to unlock.
     """
 
-def now():
-    return datetime.datetime.utcnow().replace(tzinfo=pytz.UTC)
-
 class LockOwnerSchema(colander.SchemaNode):
     title = 'Owner'
     schema_type = colander.Int
diff --git a/substanced/locking/tests/test_init.py b/substanced/locking/tests/test_init.py
index 0834ba00..1247a324 100644
--- a/substanced/locking/tests/test_init.py
+++ b/substanced/locking/tests/test_init.py
@@ -20,16 +20,6 @@ def test_ctor(self):
         inst = self._makeOne('lock')
         self.assertEqual(inst.lock, 'lock')
 
-class Test_now(unittest.TestCase):
-    def _callFUT(self):
-        from .. import now
-        return now()
-
-    def test_it(self):
-        from pytz import UTC
-        result = self._callFUT()
-        self.assertEqual(result.tzinfo, UTC)
-
 class TestLockOwnerSchema(unittest.TestCase):
     def _makeOne(self):
         from .. import LockOwnerSchema
@@ -210,18 +200,18 @@ def test_ctor(self):
         self.assertEqual(inst.comment, 'comment')
 
     def test_refresh(self):
-        import datetime
+        from .. import now
         inst = self._makeOne()
-        now = datetime.datetime.utcnow()
-        inst.refresh(when=now)
-        self.assertEqual(inst.last_refresh, now)
+        NOW = now()
+        inst.refresh(when=NOW)
+        self.assertEqual(inst.last_refresh, NOW)
 
     def test_refresh_with_timeout(self):
-        import datetime
+        from .. import now
         inst = self._makeOne()
-        now = datetime.datetime.utcnow()
-        inst.refresh(timeout=30, when=now)
-        self.assertEqual(inst.last_refresh, now)
+        NOW = now()
+        inst.refresh(timeout=30, when=NOW)
+        self.assertEqual(inst.last_refresh, NOW)
         self.assertEqual(inst.timeout, 30)
 
     def test_expires_timeout_is_None(self):
@@ -231,11 +221,12 @@ def test_expires_timeout_is_None(self):
 
     def test_expires_timeout_is_int(self):
         import datetime
+        from .. import now
         inst = self._makeOne()
         inst.timeout = 30
-        now = datetime.datetime.utcnow()
-        inst.last_refresh = now
-        self.assertEqual(inst.expires(), now + datetime.timedelta(seconds=30))
+        NOW = now()
+        inst.last_refresh = NOW
+        self.assertEqual(inst.expires(), NOW + datetime.timedelta(seconds=30))
 
     def test_is_valid_expires_timeout_is_None(self):
         inst = self._makeOne()
@@ -244,31 +235,34 @@ def test_is_valid_expires_timeout_is_None(self):
 
     def test_is_valid_expires_timeout_is_int(self):
         import datetime
+        from .. import now
         inst = self._makeOne()
         inst.timeout = 30
-        now = datetime.datetime.utcnow()
-        future = now + datetime.timedelta(seconds=60)
-        inst.last_refresh = now
-        self.assertTrue(inst.is_valid(now))
-        self.assertFalse(inst.is_valid(future))
+        NOW = now()
+        FUTURE = NOW + datetime.timedelta(seconds=60)
+        inst.last_refresh = NOW
+        self.assertTrue(inst.is_valid(NOW))
+        self.assertFalse(inst.is_valid(FUTURE))
 
     def test_is_valid_expires_resource_id_exists(self):
         import datetime
+        from .. import now
         inst = self._makeOne()
         inst.timeout = 30
-        now = datetime.datetime.utcnow()
-        inst.last_refresh = now
+        NOW = now()
+        inst.last_refresh = NOW
         inst.__objectmap__ = DummyObjectMap([1])
-        self.assertTrue(inst.is_valid(now))
+        self.assertTrue(inst.is_valid(NOW))
 
     def test_is_valid_expires_resource_id_notexist(self):
         import datetime
+        from .. import now
         inst = self._makeOne()
         inst.timeout = 30
-        now = datetime.datetime.utcnow()
-        inst.last_refresh = now
+        NOW = now()
+        inst.last_refresh = NOW
         inst.__objectmap__ = DummyObjectMap([])
-        self.assertFalse(inst.is_valid(now))
+        self.assertFalse(inst.is_valid(NOW))
 
     def test_depth_wo_infinite(self):
         inst = self._makeOne(infinite=False)
diff --git a/substanced/util/__init__.py b/substanced/util/__init__.py
index f10db34f..0909644d 100644
--- a/substanced/util/__init__.py
+++ b/substanced/util/__init__.py
@@ -3,6 +3,7 @@
     import cProfile as _profile
 except ImportError: # pragma: no cover (pypy)
     import profile as _profile
+import datetime
 import itertools
 import json
 import math
@@ -30,6 +31,9 @@
 
 _marker = object()
 
+def now():
+    return datetime.datetime.now(datetime.timezone.utc)
+
 class JsonDict(dict):
     def __str__(self):
         return json.dumps(self)
diff --git a/substanced/util/test_it.py b/substanced/util/test_it.py
index a67cadf3..6f73fd6a 100644
--- a/substanced/util/test_it.py
+++ b/substanced/util/test_it.py
@@ -4,6 +4,17 @@
 
 from . import _marker
 
+class Test_now(unittest.TestCase):
+    def _callFUT(self):
+        from . import now
+        return now()
+
+    def test_it(self):
+        import datetime
+
+        result = self._callFUT()
+        self.assertIs(result.tzinfo, datetime.timezone.utc)
+
 class Test__postorder(unittest.TestCase):
     def setUp(self):
         testing.setUp()
@@ -391,8 +402,8 @@ def _callFUT(self, d):
 
     def test_it(self):
         import calendar
-        import datetime
-        d = datetime.datetime.utcnow()
+        from . import now
+        d = now()
         result = self._callFUT(d)
         timetime = calendar.timegm(d.timetuple())
         val = int(timetime) // 100