diff --git a/typed_python/Codebase_test.py b/tests/Codebase_test.py
similarity index 100%
rename from typed_python/Codebase_test.py
rename to tests/Codebase_test.py
diff --git a/typed_python/array/array_test.py b/tests/array/array_test.py
similarity index 100%
rename from typed_python/array/array_test.py
rename to tests/array/array_test.py
diff --git a/typed_python/lib/datetime/chrono_test.py b/tests/chrono_test.py
similarity index 100%
rename from typed_python/lib/datetime/chrono_test.py
rename to tests/chrono_test.py
diff --git a/typed_python/class_types_test.py b/tests/class_types_test.py
similarity index 99%
rename from typed_python/class_types_test.py
rename to tests/class_types_test.py
index 6ed3a271d..3a9331918 100644
--- a/typed_python/class_types_test.py
+++ b/tests/class_types_test.py
@@ -91,7 +91,7 @@ def f(self, y) -> str:  # noqa: F811
 class NativeClassTypesTests(unittest.TestCase):
     def test_class_name(self):
         assert ClassWithInit.__name__ == 'ClassWithInit'
-        assert ClassWithInit.__module__ == 'typed_python.class_types_test'
+        assert ClassWithInit.__module__ == 'class_types_test'
         assert ClassWithInit.__qualname__ == 'ClassWithInit'
 
     def test_member_default_value(self):
diff --git a/typed_python/compiler/tests/__init__.py b/tests/compiler/__init__.py
similarity index 100%
rename from typed_python/compiler/tests/__init__.py
rename to tests/compiler/__init__.py
diff --git a/typed_python/compiler/tests/alternative_compilation_test.py b/tests/compiler/alternative_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/alternative_compilation_test.py
rename to tests/compiler/alternative_compilation_test.py
diff --git a/typed_python/compiler/tests/any_all_compilation_test.py b/tests/compiler/any_all_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/any_all_compilation_test.py
rename to tests/compiler/any_all_compilation_test.py
diff --git a/typed_python/compiler/tests/arithmetic_compilation_test.py b/tests/compiler/arithmetic_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/arithmetic_compilation_test.py
rename to tests/compiler/arithmetic_compilation_test.py
diff --git a/typed_python/compiler/tests/builtin_compilation_test.py b/tests/compiler/builtin_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/builtin_compilation_test.py
rename to tests/compiler/builtin_compilation_test.py
diff --git a/typed_python/compiler/tests/bytes_compilation_test.py b/tests/compiler/bytes_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/bytes_compilation_test.py
rename to tests/compiler/bytes_compilation_test.py
diff --git a/typed_python/compiler/tests/class_compilation_test.py b/tests/compiler/class_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/class_compilation_test.py
rename to tests/compiler/class_compilation_test.py
diff --git a/typed_python/compiler/tests/closures_test.py b/tests/compiler/closures_test.py
similarity index 100%
rename from typed_python/compiler/tests/closures_test.py
rename to tests/compiler/closures_test.py
diff --git a/typed_python/compiler/compiler_cache_test.py b/tests/compiler/compiler_cache_test.py
similarity index 100%
rename from typed_python/compiler/compiler_cache_test.py
rename to tests/compiler/compiler_cache_test.py
diff --git a/typed_python/compiler/tests/compiler_typed_python_comparison_test.py b/tests/compiler/compiler_typed_python_comparison_test.py
similarity index 100%
rename from typed_python/compiler/tests/compiler_typed_python_comparison_test.py
rename to tests/compiler/compiler_typed_python_comparison_test.py
diff --git a/typed_python/compiler/tests/compiling_type_operations_test.py b/tests/compiler/compiling_type_operations_test.py
similarity index 100%
rename from typed_python/compiler/tests/compiling_type_operations_test.py
rename to tests/compiler/compiling_type_operations_test.py
diff --git a/typed_python/compiler/tests/const_dict_compilation_test.py b/tests/compiler/const_dict_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/const_dict_compilation_test.py
rename to tests/compiler/const_dict_compilation_test.py
diff --git a/typed_python/compiler/tests/conversion_test.py b/tests/compiler/conversion_test.py
similarity index 100%
rename from typed_python/compiler/tests/conversion_test.py
rename to tests/compiler/conversion_test.py
diff --git a/typed_python/compiler/tests/dict_compilation_test.py b/tests/compiler/dict_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/dict_compilation_test.py
rename to tests/compiler/dict_compilation_test.py
diff --git a/typed_python/compiler/tests/entrypoint_test.py b/tests/compiler/entrypoint_test.py
similarity index 100%
rename from typed_python/compiler/tests/entrypoint_test.py
rename to tests/compiler/entrypoint_test.py
diff --git a/typed_python/compiler/tests/exception_handling_test.py b/tests/compiler/exception_handling_test.py
similarity index 100%
rename from typed_python/compiler/tests/exception_handling_test.py
rename to tests/compiler/exception_handling_test.py
diff --git a/typed_python/compiler/tests/exceptions_from_c_code_test.py b/tests/compiler/exceptions_from_c_code_test.py
similarity index 100%
rename from typed_python/compiler/tests/exceptions_from_c_code_test.py
rename to tests/compiler/exceptions_from_c_code_test.py
diff --git a/typed_python/compiler/tests/function_signature_calculator_test.py b/tests/compiler/function_signature_calculator_test.py
similarity index 100%
rename from typed_python/compiler/tests/function_signature_calculator_test.py
rename to tests/compiler/function_signature_calculator_test.py
diff --git a/typed_python/compiler/tests/generators_test.py b/tests/compiler/generators_test.py
similarity index 100%
rename from typed_python/compiler/tests/generators_test.py
rename to tests/compiler/generators_test.py
diff --git a/typed_python/compiler/tests/hash_compilation_test.py b/tests/compiler/hash_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/hash_compilation_test.py
rename to tests/compiler/hash_compilation_test.py
diff --git a/typed_python/compiler/tests/held_class_compilation_test.py b/tests/compiler/held_class_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/held_class_compilation_test.py
rename to tests/compiler/held_class_compilation_test.py
diff --git a/typed_python/compiler/tests/held_class_interpreter_semantics_test.py b/tests/compiler/held_class_interpreter_semantics_test.py
similarity index 100%
rename from typed_python/compiler/tests/held_class_interpreter_semantics_test.py
rename to tests/compiler/held_class_interpreter_semantics_test.py
diff --git a/typed_python/compiler/tests/isinstance_compilation_test.py b/tests/compiler/isinstance_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/isinstance_compilation_test.py
rename to tests/compiler/isinstance_compilation_test.py
diff --git a/typed_python/compiler/tests/list_of_compilation_test.py b/tests/compiler/list_of_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/list_of_compilation_test.py
rename to tests/compiler/list_of_compilation_test.py
diff --git a/typed_python/compiler/llvm_compiler_test.py b/tests/compiler/llvm_compiler_test.py
similarity index 100%
rename from typed_python/compiler/llvm_compiler_test.py
rename to tests/compiler/llvm_compiler_test.py
diff --git a/typed_python/compiler/tests/masquerade_test.py b/tests/compiler/masquerade_test.py
similarity index 100%
rename from typed_python/compiler/tests/masquerade_test.py
rename to tests/compiler/masquerade_test.py
diff --git a/typed_python/compiler/tests/math_functions_compilation_test.py b/tests/compiler/math_functions_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/math_functions_compilation_test.py
rename to tests/compiler/math_functions_compilation_test.py
diff --git a/typed_python/compiler/merge_type_wrappers_test.py b/tests/compiler/merge_type_wrappers_test.py
similarity index 100%
rename from typed_python/compiler/merge_type_wrappers_test.py
rename to tests/compiler/merge_type_wrappers_test.py
diff --git a/typed_python/compiler/tests/multithreading_test.py b/tests/compiler/multithreading_test.py
similarity index 100%
rename from typed_python/compiler/tests/multithreading_test.py
rename to tests/compiler/multithreading_test.py
diff --git a/typed_python/compiler/tests/named_tuple_subclass_compilation_test.py b/tests/compiler/named_tuple_subclass_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/named_tuple_subclass_compilation_test.py
rename to tests/compiler/named_tuple_subclass_compilation_test.py
diff --git a/typed_python/compiler/native_ast_to_llvm_test.py b/tests/compiler/native_ast_to_llvm_test.py
similarity index 100%
rename from typed_python/compiler/native_ast_to_llvm_test.py
rename to tests/compiler/native_ast_to_llvm_test.py
diff --git a/typed_python/compiler/tests/numpy_interaction_test.py b/tests/compiler/numpy_interaction_test.py
similarity index 100%
rename from typed_python/compiler/tests/numpy_interaction_test.py
rename to tests/compiler/numpy_interaction_test.py
diff --git a/typed_python/compiler/tests/one_of_compilation_test.py b/tests/compiler/one_of_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/one_of_compilation_test.py
rename to tests/compiler/one_of_compilation_test.py
diff --git a/typed_python/compiler/tests/operator_is_compilation_test.py b/tests/compiler/operator_is_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/operator_is_compilation_test.py
rename to tests/compiler/operator_is_compilation_test.py
diff --git a/typed_python/compiler/tests/pointer_to_compilation_test.py b/tests/compiler/pointer_to_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/pointer_to_compilation_test.py
rename to tests/compiler/pointer_to_compilation_test.py
diff --git a/typed_python/compiler/python_ast_analysis_test.py b/tests/compiler/python_ast_analysis_test.py
similarity index 100%
rename from typed_python/compiler/python_ast_analysis_test.py
rename to tests/compiler/python_ast_analysis_test.py
diff --git a/typed_python/compiler/tests/python_object_of_type_compilation_test.py b/tests/compiler/python_object_of_type_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/python_object_of_type_compilation_test.py
rename to tests/compiler/python_object_of_type_compilation_test.py
diff --git a/typed_python/compiler/tests/range_compilation_test.py b/tests/compiler/range_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/range_compilation_test.py
rename to tests/compiler/range_compilation_test.py
diff --git a/typed_python/compiler/tests/serialization_compilation_test.py b/tests/compiler/serialization_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/serialization_compilation_test.py
rename to tests/compiler/serialization_compilation_test.py
diff --git a/typed_python/compiler/tests/set_compilation_test.py b/tests/compiler/set_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/set_compilation_test.py
rename to tests/compiler/set_compilation_test.py
diff --git a/typed_python/compiler/tests/string_compilation_test.py b/tests/compiler/string_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/string_compilation_test.py
rename to tests/compiler/string_compilation_test.py
diff --git a/typed_python/compiler/tests/subclass_of_test.py b/tests/compiler/subclass_of_test.py
similarity index 100%
rename from typed_python/compiler/tests/subclass_of_test.py
rename to tests/compiler/subclass_of_test.py
diff --git a/typed_python/compiler/tests/time_compilation_test.py b/tests/compiler/time_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/time_compilation_test.py
rename to tests/compiler/time_compilation_test.py
diff --git a/typed_python/compiler/tests/tuple_compilation_test.py b/tests/compiler/tuple_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/tuple_compilation_test.py
rename to tests/compiler/tuple_compilation_test.py
diff --git a/typed_python/compiler/tests/tuple_of_compilation_test.py b/tests/compiler/tuple_of_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/tuple_of_compilation_test.py
rename to tests/compiler/tuple_of_compilation_test.py
diff --git a/typed_python/compiler/tests/type_conversion_test.py b/tests/compiler/type_conversion_test.py
similarity index 100%
rename from typed_python/compiler/tests/type_conversion_test.py
rename to tests/compiler/type_conversion_test.py
diff --git a/typed_python/compiler/tests/type_function_compilation_test.py b/tests/compiler/type_function_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/type_function_compilation_test.py
rename to tests/compiler/type_function_compilation_test.py
diff --git a/typed_python/compiler/tests/type_inference_test.py b/tests/compiler/type_inference_test.py
similarity index 100%
rename from typed_python/compiler/tests/type_inference_test.py
rename to tests/compiler/type_inference_test.py
diff --git a/typed_python/compiler/tests/type_of_instances_compilation_test.py b/tests/compiler/type_of_instances_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/type_of_instances_compilation_test.py
rename to tests/compiler/type_of_instances_compilation_test.py
diff --git a/typed_python/compiler/tests/typed_function_compilation_test.py b/tests/compiler/typed_function_compilation_test.py
similarity index 100%
rename from typed_python/compiler/tests/typed_function_compilation_test.py
rename to tests/compiler/typed_function_compilation_test.py
diff --git a/typed_python/lib/datetime/date_formatter_test.py b/tests/date_formatter_test.py
similarity index 100%
rename from typed_python/lib/datetime/date_formatter_test.py
rename to tests/date_formatter_test.py
diff --git a/typed_python/lib/datetime/date_parser_test.py b/tests/date_parser_test.py
similarity index 100%
rename from typed_python/lib/datetime/date_parser_test.py
rename to tests/date_parser_test.py
diff --git a/typed_python/lib/datetime/date_time_test.py b/tests/date_time_test.py
similarity index 99%
rename from typed_python/lib/datetime/date_time_test.py
rename to tests/date_time_test.py
index 1f14deb99..5aadc4151 100644
--- a/typed_python/lib/datetime/date_time_test.py
+++ b/tests/date_time_test.py
@@ -16,7 +16,7 @@
     OneFoldOnlyError,
     PytzTimezone,
 )
-from typed_python.lib.datetime.date_parser_test import get_datetimes_in_range
+from date_parser_test import get_datetimes_in_range
 from typed_python.lib.timestamp import Timestamp
 
 
diff --git a/typed_python/lib/datetime/date_time_util_test.py b/tests/date_time_util_test.py
similarity index 100%
rename from typed_python/lib/datetime/date_time_util_test.py
rename to tests/date_time_util_test.py
diff --git a/typed_python/deep_bytecount_test.py b/tests/deep_bytecount_test.py
similarity index 100%
rename from typed_python/deep_bytecount_test.py
rename to tests/deep_bytecount_test.py
diff --git a/typed_python/deepcopy_test.py b/tests/deepcopy_test.py
similarity index 100%
rename from typed_python/deepcopy_test.py
rename to tests/deepcopy_test.py
diff --git a/typed_python/forward_types_test.py b/tests/forward_types_test.py
similarity index 100%
rename from typed_python/forward_types_test.py
rename to tests/forward_types_test.py
diff --git a/typed_python/function_signature_test.py b/tests/function_signature_test.py
similarity index 100%
rename from typed_python/function_signature_test.py
rename to tests/function_signature_test.py
diff --git a/typed_python/function_types_test.py b/tests/function_types_test.py
similarity index 100%
rename from typed_python/function_types_test.py
rename to tests/function_types_test.py
diff --git a/typed_python/macro_test.py b/tests/macro_test.py
similarity index 100%
rename from typed_python/macro_test.py
rename to tests/macro_test.py
diff --git a/typed_python/lib/map_test.py b/tests/map_test.py
similarity index 100%
rename from typed_python/lib/map_test.py
rename to tests/map_test.py
diff --git a/typed_python/module_representation_test.py b/tests/module_representation_test.py
similarity index 100%
rename from typed_python/module_representation_test.py
rename to tests/module_representation_test.py
diff --git a/typed_python/module_test.py b/tests/module_test.py
similarity index 100%
rename from typed_python/module_test.py
rename to tests/module_test.py
diff --git a/typed_python/lib/pmap_test.py b/tests/pmap_test.py
similarity index 100%
rename from typed_python/lib/pmap_test.py
rename to tests/pmap_test.py
diff --git a/typed_python/python_ast_test.py b/tests/python_ast_test.py
similarity index 100%
rename from typed_python/python_ast_test.py
rename to tests/python_ast_test.py
diff --git a/typed_python/lib/reduce_test.py b/tests/reduce_test.py
similarity index 100%
rename from typed_python/lib/reduce_test.py
rename to tests/reduce_test.py
diff --git a/typed_python/lib/sorted_dict_test.py b/tests/sorted_dict_test.py
similarity index 100%
rename from typed_python/lib/sorted_dict_test.py
rename to tests/sorted_dict_test.py
diff --git a/typed_python/lib/sorting_test.py b/tests/sorting_test.py
similarity index 100%
rename from typed_python/lib/sorting_test.py
rename to tests/sorting_test.py
diff --git a/typed_python/lib/timestamp_test.py b/tests/timestamp_test.py
similarity index 100%
rename from typed_python/lib/timestamp_test.py
rename to tests/timestamp_test.py
diff --git a/typed_python/type_function_test.py b/tests/type_function_test.py
similarity index 99%
rename from typed_python/type_function_test.py
rename to tests/type_function_test.py
index 47d740174..11ac07352 100644
--- a/typed_python/type_function_test.py
+++ b/tests/type_function_test.py
@@ -98,7 +98,7 @@ def List(T):
 
     def test_name_and_qualname(self):
         assert TfLevelMethod.__name__ == 'TfLevelMethod'
-        assert TfLevelMethod.__module__ == 'typed_python.type_function_test'
+        assert TfLevelMethod.__module__ == 'type_function_test'
         assert TfLevelMethod.__qualname__ == 'TfLevelMethod'
 
     def test_mutually_recursive(self):
diff --git a/typed_python/type_identity_test.py b/tests/type_identity_test.py
similarity index 99%
rename from typed_python/type_identity_test.py
rename to tests/type_identity_test.py
index d32bb736e..09c42b0e8 100644
--- a/typed_python/type_identity_test.py
+++ b/tests/type_identity_test.py
@@ -60,7 +60,7 @@ def looksAtFilename():
 
 
 def looksAtFilename2():
-    return typed_python.type_identity_test.__file__
+    return __file__
 
 
 def checkHash(filesToWrite, expression):
@@ -273,7 +273,8 @@ def test_mutually_recursive_group_basic():
     X = Forward("X")
     X = X.define(TupleOf(OneOf(int, X)))
 
-    assert recursiveTypeGroup(X) == [X, OneOf(int, X)]
+    assert (recursiveTypeGroup(X) == [X, OneOf(int, X)] or
+            recursiveTypeGroup(X) == [OneOf(int, X), X])  # order-independent
 
 
 def test_mutually_recursive_group_through_functions_in_closure():
diff --git a/typed_python/typed_queue_test.py b/tests/typed_queue_test.py
similarity index 100%
rename from typed_python/typed_queue_test.py
rename to tests/typed_queue_test.py
diff --git a/typed_python/types_metadata_test.py b/tests/types_metadata_test.py
similarity index 100%
rename from typed_python/types_metadata_test.py
rename to tests/types_metadata_test.py
diff --git a/typed_python/types_named_tuple_test.py b/tests/types_named_tuple_test.py
similarity index 100%
rename from typed_python/types_named_tuple_test.py
rename to tests/types_named_tuple_test.py
diff --git a/typed_python/types_serialization_format_test.py b/tests/types_serialization_format_test.py
similarity index 100%
rename from typed_python/types_serialization_format_test.py
rename to tests/types_serialization_format_test.py
diff --git a/typed_python/types_serialization_test.py b/tests/types_serialization_test.py
similarity index 95%
rename from typed_python/types_serialization_test.py
rename to tests/types_serialization_test.py
index c5f33c2a1..d771b8906 100644
--- a/typed_python/types_serialization_test.py
+++ b/tests/types_serialization_test.py
@@ -1843,7 +1843,7 @@ def test_serialize_mutually_recursive_unnamed_forwards_tuples(self):
     def test_serialize_named_alternative(self):
         self.assertEqual(
             ModuleLevelAlternative.__module__,
-            "typed_python.types_serialization_test"
+            "types_serialization_test"
         )
 
         sc = SerializationContext()
@@ -1866,14 +1866,14 @@ def test_serialize_unnamed_recursive_alternative(self):
         )
 
     def test_serialize_module_level_class(self):
-        assert ModuleLevelClass.__module__ == 'typed_python.types_serialization_test'
+        assert ModuleLevelClass.__module__ == 'types_serialization_test'
 
         sc = SerializationContext().withoutCompression()
 
         self.assertIs(sc.deserialize(sc.serialize(ModuleLevelClass)), ModuleLevelClass)
 
         self.assertIn(
-            b'typed_python.types_serialization_test.ModuleLevelClass',
+            b'types_serialization_test.ModuleLevelClass',
             sc.serialize(ModuleLevelClass),
         )
 
@@ -1899,7 +1899,7 @@ def test_serialize_named_subclass_of_named_tuple(self):
 
         self.assertEqual(
             ModuleLevelNamedTupleSubclass.__module__,
-            "typed_python.types_serialization_test"
+            "types_serialization_test"
         )
 
         self.assertEqual(
@@ -2031,7 +2031,7 @@ def f():
         def getCellType():
             return type(f.__closure__[0])
 
-        assert callFunctionInFreshProcess(getCellType, ()) is getCellType()
+        assert callFunctionInFreshProcess(getCellType, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)}) is getCellType()
 
     def test_self_visible_base_class_forward_resolved(self):
         Base = Forward("Base")
@@ -2060,7 +2060,7 @@ def __add__(self, other: Base) -> Base:
 
             return Base, Child
 
-        Base, Child = callFunctionInFreshProcess(getOptimizer, ())
+        Base, Child = callFunctionInFreshProcess(getOptimizer, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         assert isinstance(Base() + Base() + Base(), Base)
         assert isinstance(Base() + Base() + Base(), Child)
@@ -2082,7 +2082,7 @@ def g(self):
 
             return C_
 
-        c = callFunctionInFreshProcess(C(int), ())
+        c = callFunctionInFreshProcess(C(int), (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         assert c.g() == 10
         assert c.s() is type(c)
@@ -2106,7 +2106,7 @@ def g(self):
 
             return C_
 
-        c = callFunctionInFreshProcess(C(int), ())
+        c = callFunctionInFreshProcess(C(int), (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
         assert c.g() == 10
         assert c.s() is type(c)
 
@@ -2175,7 +2175,10 @@ def makeLenProxyWeirdGlobals():
         assert lenProxy("asdf") == 4
         assert lenProxyWithNonstandardGlobals("asdf") == 4
 
-        lenProxyDeserialized = callFunctionInFreshProcess(makeLenProxyWeirdGlobals, ())
+        lenProxyDeserialized = callFunctionInFreshProcess(makeLenProxyWeirdGlobals,
+                                                          (),
+                                                          extraEnvs={'PYTHONPATH': os.path.dirname(__file__)}
+                                                          )
 
         assert lenProxyDeserialized("asdf") == 4
 
@@ -2225,7 +2228,7 @@ def seeItself(self, a, b, c, d):
 
             return SeesItself
 
-        SeesItself = callFunctionInFreshProcess(makeSeesItself, ())
+        SeesItself = callFunctionInFreshProcess(makeSeesItself, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         assert SeesItself.seeItself(1, 2, 3, 4, 5) is SeesItself
 
@@ -2275,7 +2278,7 @@ class Cls:
             def f(self):
                 return Cls
 
-        assert callFunctionInFreshProcess(Cls().f, ()) is Cls
+        assert callFunctionInFreshProcess(Cls().f, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)}) is Cls
 
     def test_serialization_preserves_forward_structure_in_classes(self):
         def getCls():
@@ -2289,7 +2292,7 @@ def f(self) -> Cls:
 
             return Cls
 
-        Cls = callFunctionInFreshProcess(getCls, (), showStdout=True)
+        Cls = callFunctionInFreshProcess(getCls, (), showStdout=True, extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
         assert Cls.f.__annotations__['return'].__typed_python_category__ == 'Forward'
 
         Cls2 = getCls()
@@ -2304,7 +2307,7 @@ class Cls:
             def f(self) -> Cls:
                 return "HI"
 
-        assert callFunctionInFreshProcess(Cls, ()).f() == "HI"
+        assert callFunctionInFreshProcess(Cls, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)}).f() == "HI"
 
     def test_can_deserialize_untyped_forward_class_methods_2(self):
         def getCls():
@@ -2318,7 +2321,7 @@ def f(self) -> Cls:
 
             return Cls
 
-        callFunctionInFreshProcess(getCls, ())
+        callFunctionInFreshProcess(getCls, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
     def test_can_deserialize_forward_class_methods_tp_class(self):
         Cls = Forward("Cls")
@@ -2330,7 +2333,7 @@ class Cls(Class):
             def f(self) -> Cls:
                 return Cls(m='HI')
 
-        assert callFunctionInFreshProcess(Cls, ()).f().m == "HI"
+        assert callFunctionInFreshProcess(Cls, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)}).f().m == "HI"
 
     def test_can_deserialize_forward_class_methods_tp_class_no_self_reference(self):
         Cls = Forward("Cls")
@@ -2342,7 +2345,7 @@ class Cls(Class):
             def f(self) -> str:
                 return "HI"
 
-        assert callFunctionInFreshProcess(Cls, ()).f() == "HI"
+        assert callFunctionInFreshProcess(Cls, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)}).f() == "HI"
 
     def test_deserialize_regular_class_retains_identity(self):
         class Cls:
@@ -2351,7 +2354,7 @@ def f(self):
                 Cls
                 return "HI"
 
-        Cls2 = type(callFunctionInFreshProcess(Cls, ()))
+        Cls2 = type(callFunctionInFreshProcess(Cls, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)}))
 
         assert identityHash(Cls).hex() == identityHash(Cls2).hex()
 
@@ -2367,7 +2370,7 @@ def f(x: float):
 
             return (f, identityHash(f))
 
-        f, identityHashOfF = callFunctionInFreshProcess(makeFunction, ())
+        f, identityHashOfF = callFunctionInFreshProcess(makeFunction, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         assert identityHash(f) == identityHashOfF
 
@@ -2383,7 +2386,7 @@ def f(x=None):
 
             return (f, identityHash(f))
 
-        f, identityHashOfF = callFunctionInFreshProcess(makeFunction, ())
+        f, identityHashOfF = callFunctionInFreshProcess(makeFunction, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         assert identityHash(f) == identityHashOfF
 
@@ -2399,7 +2402,7 @@ class Cls:
             def f(self) -> Cls:
                 return Cls()
 
-        Cls2 = type(callFunctionInFreshProcess(Cls, ()))
+        Cls2 = type(callFunctionInFreshProcess(Cls, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)}))
 
         l = recursiveTypeGroupDeepRepr(Cls).split("\n")
         r = recursiveTypeGroupDeepRepr(Cls2).split("\n")
@@ -2429,7 +2432,7 @@ class Cls(Class):
             def f(self) -> Cls:
                 return Cls()
 
-        Cls2 = type(callFunctionInFreshProcess(Cls, ()))
+        Cls2 = type(callFunctionInFreshProcess(Cls, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)}))
 
         assert identityHash(Cls) == identityHash(Cls2)
 
@@ -2468,7 +2471,7 @@ def callF(x):
             else:
                 return "FAILED"
 
-        assert callFunctionInFreshProcess(deserializeAndCall, (aChildBytes,)) == "OK"
+        assert callFunctionInFreshProcess(deserializeAndCall, (aChildBytes,), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)}) == "OK"
 
     def test_call_method_dispatch_on_two_versions_of_self_referential_class_produced_differently(self):
         def deserializeAndCall():
@@ -2492,8 +2495,8 @@ def f(self, x) -> int:
 
             return Child(), callF
 
-        child1, callF1 = callFunctionInFreshProcess(deserializeAndCall, ())
-        child2, callF2 = callFunctionInFreshProcess(deserializeAndCall, ())
+        child1, callF1 = callFunctionInFreshProcess(deserializeAndCall, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
+        child2, callF2 = callFunctionInFreshProcess(deserializeAndCall, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         assert identityHash(child1) == identityHash(child2)
         assert identityHash(callF1) == identityHash(callF2)
@@ -2526,8 +2529,8 @@ def callF(x: Child):
 
             return Base, callF
 
-        Base1, callF1 = callFunctionInFreshProcess(deserializeAndCall, ())
-        Base2, callF2 = callFunctionInFreshProcess(deserializeAndCall, ())
+        Base1, callF1 = callFunctionInFreshProcess(deserializeAndCall, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
+        Base2, callF2 = callFunctionInFreshProcess(deserializeAndCall, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         assert identityHash(Base1) == identityHash(Base2)
         assert identityHash(callF1) == identityHash(callF2)
@@ -2578,7 +2581,7 @@ def f(self, x) -> int:
 
             return SerializationContext().serialize(Child())
 
-        childBytes = callFunctionInFreshProcess(deserializeAndCall, ())
+        childBytes = callFunctionInFreshProcess(deserializeAndCall, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         child1 = SerializationContext().deserialize(childBytes)
         child2 = SerializationContext().deserialize(childBytes)
@@ -2606,7 +2609,7 @@ def aFun():
 
             return s.serialize(aFun)
 
-        childBytes = callFunctionInFreshProcess(returnSerializedForm, ())
+        childBytes = callFunctionInFreshProcess(returnSerializedForm, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         childFun = (
             SerializationContext()
@@ -2657,7 +2660,9 @@ def f(self):
 
             return (BaseClass, ChildClass, ChildClass())
 
-        BaseClass, ChildClass, childInstance = callFunctionInFreshProcess(makeClasses, ())
+        BaseClass, ChildClass, childInstance = callFunctionInFreshProcess(makeClasses,
+                                                                          (),
+                                                                          extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         assert type(BaseClass) is ABCMeta
 
@@ -2695,7 +2700,7 @@ class ChildClass(BaseClass):
 
             return (BaseClass, ChildClass, recursiveTypeGroupDeepRepr(BaseClass))
 
-        BaseClass, ChildClass, deepRepr = callFunctionInFreshProcess(makeClasses, ())
+        BaseClass, ChildClass, deepRepr = callFunctionInFreshProcess(makeClasses, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         assert type(BaseClass.getChild()) is ChildClass
 
@@ -2714,7 +2719,7 @@ def makeF():
 
             return f
 
-        f = callFunctionInFreshProcess(makeF, ())
+        f = callFunctionInFreshProcess(makeF, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         assert f(10) == 10
 
@@ -2737,7 +2742,7 @@ class Child(Base):
             return s.serialize(Child)
 
         Child2 = SerializationContext().deserialize(
-            callFunctionInFreshProcess(serializeIt, ())
+            callFunctionInFreshProcess(serializeIt, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
         )
 
         assert Child2().func() == 10
@@ -2776,7 +2781,7 @@ def makeF():
                 s = SerializationContext()
                 return s.serialize(globals['anF'])
 
-        serializedF = callFunctionInFreshProcess(makeF, ())
+        serializedF = callFunctionInFreshProcess(makeF, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         f = SerializationContext().deserialize(serializedF)
 
@@ -2813,7 +2818,7 @@ def makeC():
                 s = SerializationContext()
                 return s.serialize(globals['C'])
 
-        serializedC = callFunctionInFreshProcess(makeC, ())
+        serializedC = callFunctionInFreshProcess(makeC, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         C = SerializationContext().deserialize(serializedC)
 
@@ -2847,7 +2852,7 @@ def makeC():
                 s = SerializationContext()
                 return s.serialize(globals['C'])
 
-        serializedC = callFunctionInFreshProcess(makeC, ())
+        serializedC = callFunctionInFreshProcess(makeC, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         C = SerializationContext().deserialize(serializedC)
 
@@ -2887,8 +2892,12 @@ def makeF(modulename):
                 s = SerializationContext()
                 return s.serialize(globals['f'])
 
-        f1 = SerializationContext().deserialize(callFunctionInFreshProcess(makeF, ('asdf',)))
-        f2 = SerializationContext().deserialize(callFunctionInFreshProcess(makeF, ('asdf2',)))
+        f1 = SerializationContext().deserialize(callFunctionInFreshProcess(makeF,
+                                                                           ('asdf',),
+                                                                           extraEnvs={'PYTHONPATH': os.path.dirname(__file__)}))
+        f2 = SerializationContext().deserialize(callFunctionInFreshProcess(makeF,
+                                                                           ('asdf2',),
+                                                                           extraEnvs={'PYTHONPATH': os.path.dirname(__file__)}))
 
         def checkSame(f1, f2):
             s = SerializationContext().withoutCompression()
@@ -3023,15 +3032,14 @@ def makeC():
 
                 globals = {'__file__': path}
 
-                exec(
-                    compile(CONTENTS, path, "exec"),
-                    globals
-                )
+                exec(compile(CONTENTS, path, "exec"),
+                     globals
+                     )
 
                 s = SerializationContext()
                 return s.serialize(globals['f'])
 
-        serializedF = callFunctionInFreshProcess(makeC, ())
+        serializedF = callFunctionInFreshProcess(makeC, (), extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         f = SerializationContext().deserialize(serializedF)
 
@@ -3056,7 +3064,7 @@ def f(self):
 
             return x
 
-        x = callFunctionInFreshProcess(getX, (), showStdout=True)
+        x = callFunctionInFreshProcess(getX, (), showStdout=True, extraEnvs={'PYTHONPATH': os.path.dirname(__file__)})
 
         print(x)
         # TODO: make this True
diff --git a/typed_python/types_test.py b/tests/types_test.py
similarity index 99%
rename from typed_python/types_test.py
rename to tests/types_test.py
index 721c62b86..75e746807 100644
--- a/typed_python/types_test.py
+++ b/tests/types_test.py
@@ -185,8 +185,8 @@ def pickRandomly(self):
 
 class TypesTests(unittest.TestCase):
     def test_alternative_module(self):
-        assert AnAlternative.__module__ == 'typed_python.types_test'
-        assert AForwardAlternative.__module__ == 'typed_python.types_test'
+        assert AnAlternative.__module__ == 'types_test'
+        assert AForwardAlternative.__module__ == 'types_test'
 
     def test_refcount_bug_with_simple_string(self):
         with self.assertRaisesRegex(TypeError, "first argument to refcount '111' not a permitted Type"):
diff --git a/tox.ini b/tox.ini
index 25734eeb5..cfd6cb88f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -14,7 +14,7 @@ commands =
 
 [pytest]
 testpaths =
-    typed_python
+    tests
 
 log_level = INFO
 log_format = [%(asctime)s.%(msecs)03d] %(levelname)8s %(filename)30s:%(lineno)4s | %(threadName)10s | %(message)s