diff --git a/libtbx/clusterTests.py b/libtbx/clusterTests.py
index 1274230c6b..7637878dd9 100644
--- a/libtbx/clusterTests.py
+++ b/libtbx/clusterTests.py
@@ -187,11 +187,11 @@ def testLostFunctionReference(self):
 if (__name__ == "__main__"):
   unittest.TextTestRunner(stream=sys.stdout, verbosity=0).run(
       unittest.TestSuite((
-            unittest.makeSuite(HClusterSmallListTestCase),
-            unittest.makeSuite(HClusterIntegerTestCase),
-            unittest.makeSuite(HClusterStringTestCase),
-            unittest.makeSuite(KClusterSmallListTestCase),
-            unittest.makeSuite(KCluster2DTestCase),
-            unittest.makeSuite(KClusterSFBugs),
+            unittest.defaultTestLoader.loadTestsFromTestCase(HClusterSmallListTestCase),
+            unittest.defaultTestLoader.loadTestsFromTestCase(HClusterIntegerTestCase),
+            unittest.defaultTestLoader.loadTestsFromTestCase(HClusterStringTestCase),
+            unittest.defaultTestLoader.loadTestsFromTestCase(KClusterSmallListTestCase),
+            unittest.defaultTestLoader.loadTestsFromTestCase(KCluster2DTestCase),
+            unittest.defaultTestLoader.loadTestsFromTestCase(KClusterSFBugs),
          ))
       )
diff --git a/libtbx/object_oriented_patterns.py b/libtbx/object_oriented_patterns.py
index 9c331b9095..0a7b8c5c39 100644
--- a/libtbx/object_oriented_patterns.py
+++ b/libtbx/object_oriented_patterns.py
@@ -19,6 +19,9 @@ def __init__(cls, name, bases, namespace, **kwds):
         if sys.hexversion >= 0x03000000:
           if name in ('__qualname__',):
             continue
+        if sys.version_info.major == 3 and sys.version_info.minor >= 13:
+          if name in ('__firstlineno__', '__static_attributes__'):
+            continue
         assert not hasattr(target_class, name), (
           "class %s already has attribute '%s'"
           % (target_class.__name__, name))
diff --git a/libtbx/tst_object_oriented_patterns.py b/libtbx/tst_object_oriented_patterns.py
index 6f27522468..a6e0cee57d 100644
--- a/libtbx/tst_object_oriented_patterns.py
+++ b/libtbx/tst_object_oriented_patterns.py
@@ -65,7 +65,9 @@ def f(x):
     pass
   else:
     raise Exception_expected
-  assert mf.__doc__ == """ Documentation for function f """
+  # Python 3.13 automatically strips leading spaces
+  assert mf.__doc__ == """ Documentation for function f """ \
+    or mf.__doc__ == """Documentation for function f """
 
 def exercise_memoize_with_injector():
   class foo(object):
@@ -97,7 +99,8 @@ def f(self, x):
   assert diagnostic == ['+']*4
   assert o1.f(1) == 2
   assert diagnostic == ['+']*4
-  assert o1.f.__doc__ == " Documentation for method f "
+  assert o1.f.__doc__ == " Documentation for method f " \
+    or o1.f.__doc__ == "Documentation for method f "
 
   class _foo_extension(oop.injector, foo):
     def g(self, n):