diff --git a/.meta.toml b/.meta.toml
index 2b7a7f4..81c8906 100644
--- a/.meta.toml
+++ b/.meta.toml
@@ -29,7 +29,7 @@ testenv-setenv = [
 testenv-commands = [
     "python -V",
     "pip list",
-    "pytest --cov=src --cov-report= {posargs}",
+    "pytest --cov=src --cov=tests --cov-report= {posargs}",
     ]
 testenv-additional = [
     "",
@@ -51,7 +51,7 @@ testenv-additional = [
     "depends = py36,py37,py38,py39,py39-datetime,py310,py311,coverage",
     ]
 coverage-basepython = "python3.8"
-coverage-command = "pytest --cov=src --cov-report= {posargs}"
+coverage-command = "pytest --cov=src --cov=tests --cov-report= {posargs}"
 coverage-setenv = [
     "COVERAGE_FILE=.coverage",
     ]
@@ -64,6 +64,7 @@ additional-rules = [
     "recursive-include docs *.ast",
     "recursive-include docs *.bat",
     "recursive-include docs *.jpg",
+    "recursive-include tests *.py",
     ]
 
 [check-manifest]
diff --git a/CHANGES.rst b/CHANGES.rst
index d30ed10..8203ff8 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -17,9 +17,6 @@ Features
 
 - Fix code to run on Python 3.11.0b3.
 
-- Move ``tests`` directory into ``src``.
-  (`#232 <https://github.com/zopefoundation/RestrictedPython/pull/232>`_)
-
 
 5.2 (2021-11-19)
 ----------------
diff --git a/MANIFEST.in b/MANIFEST.in
index 0d8944f..a1bb705 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -15,3 +15,4 @@ recursive-include src *.py
 recursive-include docs *.ast
 recursive-include docs *.bat
 recursive-include docs *.jpg
+recursive-include tests *.py
diff --git a/src/RestrictedPython/tests/transformer/__init__.py b/src/RestrictedPython/tests/transformer/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/src/RestrictedPython/tests/transformer/operators/__init__.py b/src/RestrictedPython/tests/transformer/operators/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/src/RestrictedPython/tests/__init__.py b/tests/__init__.py
similarity index 100%
rename from src/RestrictedPython/tests/__init__.py
rename to tests/__init__.py
diff --git a/src/RestrictedPython/tests/builtins/test_limits.py b/tests/builtins/test_limits.py
similarity index 100%
rename from src/RestrictedPython/tests/builtins/test_limits.py
rename to tests/builtins/test_limits.py
index 1481946..8661960 100644
--- a/src/RestrictedPython/tests/builtins/test_limits.py
+++ b/tests/builtins/test_limits.py
@@ -1,9 +1,9 @@
-import pytest
-
 from RestrictedPython.Limits import limited_list
 from RestrictedPython.Limits import limited_range
 from RestrictedPython.Limits import limited_tuple
 
+import pytest
+
 
 def test_limited_range_length_1():
     result = limited_range(1)
diff --git a/src/RestrictedPython/tests/builtins/test_utilities.py b/tests/builtins/test_utilities.py
similarity index 100%
rename from src/RestrictedPython/tests/builtins/test_utilities.py
rename to tests/builtins/test_utilities.py
diff --git a/src/RestrictedPython/tests/helper.py b/tests/helper.py
similarity index 99%
rename from src/RestrictedPython/tests/helper.py
rename to tests/helper.py
index 46efe2b..25cf3bd 100644
--- a/src/RestrictedPython/tests/helper.py
+++ b/tests/helper.py
@@ -1,7 +1,8 @@
-import RestrictedPython.Guards
 from RestrictedPython import compile_restricted_eval
 from RestrictedPython import compile_restricted_exec
 
+import RestrictedPython.Guards
+
 
 def _compile(compile_func, source):
     """Compile some source with a compile func."""
diff --git a/src/RestrictedPython/tests/test_Guards.py b/tests/test_Guards.py
similarity index 98%
rename from src/RestrictedPython/tests/test_Guards.py
rename to tests/test_Guards.py
index 01ec228..6fbf2ae 100644
--- a/src/RestrictedPython/tests/test_Guards.py
+++ b/tests/test_Guards.py
@@ -1,13 +1,12 @@
-import pytest
-
 from RestrictedPython import compile_restricted_exec
 from RestrictedPython.Guards import guarded_unpack_sequence
 from RestrictedPython.Guards import safe_builtins
 from RestrictedPython.Guards import safe_globals
 from RestrictedPython.Guards import safer_getattr
+from tests.helper import restricted_eval
+from tests.helper import restricted_exec
 
-from .helper import restricted_eval
-from .helper import restricted_exec
+import pytest
 
 
 def _write_(x):
diff --git a/src/RestrictedPython/tests/test_NamedExpr.py b/tests/test_NamedExpr.py
similarity index 99%
rename from src/RestrictedPython/tests/test_NamedExpr.py
rename to tests/test_NamedExpr.py
index 308d0dd..be064e3 100644
--- a/src/RestrictedPython/tests/test_NamedExpr.py
+++ b/tests/test_NamedExpr.py
@@ -3,12 +3,11 @@
 
 from ast import NodeTransformer
 from ast import parse
-from unittest import TestCase
-from unittest import skipUnless
-
 from RestrictedPython import compile_restricted
 from RestrictedPython import safe_globals
 from RestrictedPython._compat import IS_PY38_OR_GREATER
+from unittest import skipUnless
+from unittest import TestCase
 
 
 @skipUnless(IS_PY38_OR_GREATER, "Feature available for Python 3.8+")
diff --git a/src/RestrictedPython/tests/test_Utilities.py b/tests/test_Utilities.py
similarity index 100%
rename from src/RestrictedPython/tests/test_Utilities.py
rename to tests/test_Utilities.py
diff --git a/src/RestrictedPython/tests/test_compile.py b/tests/test_compile.py
similarity index 99%
rename from src/RestrictedPython/tests/test_compile.py
rename to tests/test_compile.py
index 7d67381..4ef3869 100644
--- a/src/RestrictedPython/tests/test_compile.py
+++ b/tests/test_compile.py
@@ -1,17 +1,15 @@
-import platform
-import types
-
-import pytest
-
-from RestrictedPython import CompileResult
 from RestrictedPython import compile_restricted
 from RestrictedPython import compile_restricted_eval
 from RestrictedPython import compile_restricted_exec
 from RestrictedPython import compile_restricted_single
+from RestrictedPython import CompileResult
 from RestrictedPython._compat import IS_PY38_OR_GREATER
 from RestrictedPython._compat import IS_PY310_OR_GREATER
+from tests.helper import restricted_eval
 
-from .helper import restricted_eval
+import platform
+import pytest
+import types
 
 
 def test_compile__compile_restricted_invalid_code_input():
diff --git a/src/RestrictedPython/tests/test_compile_restricted_function.py b/tests/test_compile_restricted_function.py
similarity index 99%
rename from src/RestrictedPython/tests/test_compile_restricted_function.py
rename to tests/test_compile_restricted_function.py
index 8d9de6b..5c81f86 100644
--- a/src/RestrictedPython/tests/test_compile_restricted_function.py
+++ b/tests/test_compile_restricted_function.py
@@ -1,10 +1,9 @@
-from types import FunctionType
-
-from RestrictedPython import PrintCollector
 from RestrictedPython import compile_restricted_function
+from RestrictedPython import PrintCollector
 from RestrictedPython import safe_builtins
 from RestrictedPython._compat import IS_PY38_OR_GREATER
 from RestrictedPython._compat import IS_PY310_OR_GREATER
+from types import FunctionType
 
 
 def test_compile_restricted_function():
diff --git a/src/RestrictedPython/tests/test_eval.py b/tests/test_eval.py
similarity index 100%
rename from src/RestrictedPython/tests/test_eval.py
rename to tests/test_eval.py
index 1225928..d1acf10 100644
--- a/src/RestrictedPython/tests/test_eval.py
+++ b/tests/test_eval.py
@@ -1,7 +1,7 @@
-import pytest
-
 from RestrictedPython.Eval import RestrictionCapableEval
 
+import pytest
+
 
 exp = """
     {'a':[m.pop()]}['a'] \
diff --git a/src/RestrictedPython/tests/test_imports.py b/tests/test_imports.py
similarity index 97%
rename from src/RestrictedPython/tests/test_imports.py
rename to tests/test_imports.py
index 81ca056..79f86d3 100644
--- a/src/RestrictedPython/tests/test_imports.py
+++ b/tests/test_imports.py
@@ -2,12 +2,11 @@
 Tests about imports
 """
 
-import pytest
-
 from RestrictedPython import compile_restricted_exec
 from RestrictedPython import safe_builtins
+from tests.helper import restricted_exec
 
-from .helper import restricted_exec
+import pytest
 
 
 OS_IMPORT_EXAMPLE = """
diff --git a/src/RestrictedPython/tests/test_iterating_over_dict_items.py b/tests/test_iterating_over_dict_items.py
similarity index 100%
rename from src/RestrictedPython/tests/test_iterating_over_dict_items.py
rename to tests/test_iterating_over_dict_items.py
index 7157bab..b45d6d0 100644
--- a/src/RestrictedPython/tests/test_iterating_over_dict_items.py
+++ b/tests/test_iterating_over_dict_items.py
@@ -1,10 +1,10 @@
-import pytest
-
 from RestrictedPython import compile_restricted_exec
 from RestrictedPython import safe_globals
 from RestrictedPython.Eval import default_guarded_getiter
 from RestrictedPython.Guards import guarded_iter_unpack_sequence
 
+import pytest
+
 
 ITERATE_OVER_DICT_ITEMS = """
 d = {'a': 'b'}
diff --git a/src/RestrictedPython/tests/test_print_function.py b/tests/test_print_function.py
similarity index 99%
rename from src/RestrictedPython/tests/test_print_function.py
rename to tests/test_print_function.py
index f8e9282..d29fa18 100644
--- a/src/RestrictedPython/tests/test_print_function.py
+++ b/tests/test_print_function.py
@@ -1,6 +1,7 @@
-import RestrictedPython
 from RestrictedPython.PrintCollector import PrintCollector
 
+import RestrictedPython
+
 
 compiler = RestrictedPython.compile.compile_restricted_exec
 
diff --git a/src/RestrictedPython/tests/transformer/operators/test_arithmetic_operators.py b/tests/transformer/operators/test_arithmetic_operators.py
similarity index 94%
rename from src/RestrictedPython/tests/transformer/operators/test_arithmetic_operators.py
rename to tests/transformer/operators/test_arithmetic_operators.py
index 99197ec..209eb50 100644
--- a/src/RestrictedPython/tests/transformer/operators/test_arithmetic_operators.py
+++ b/tests/transformer/operators/test_arithmetic_operators.py
@@ -1,6 +1,5 @@
 from RestrictedPython import compile_restricted_eval
-
-from ...helper import restricted_eval
+from tests.helper import restricted_eval
 
 
 # Arithmetic Operators
diff --git a/src/RestrictedPython/tests/transformer/operators/test_bit_wise_operators.py b/tests/transformer/operators/test_bit_wise_operators.py
similarity index 90%
rename from src/RestrictedPython/tests/transformer/operators/test_bit_wise_operators.py
rename to tests/transformer/operators/test_bit_wise_operators.py
index 281f1c9..839c41f 100644
--- a/src/RestrictedPython/tests/transformer/operators/test_bit_wise_operators.py
+++ b/tests/transformer/operators/test_bit_wise_operators.py
@@ -1,4 +1,4 @@
-from ...helper import restricted_eval
+from tests.helper import restricted_eval
 
 
 def test_BitAnd():
diff --git a/src/RestrictedPython/tests/transformer/operators/test_bool_operators.py b/tests/transformer/operators/test_bool_operators.py
similarity index 83%
rename from src/RestrictedPython/tests/transformer/operators/test_bool_operators.py
rename to tests/transformer/operators/test_bool_operators.py
index aa41f5b..9bb8625 100644
--- a/src/RestrictedPython/tests/transformer/operators/test_bool_operators.py
+++ b/tests/transformer/operators/test_bool_operators.py
@@ -1,4 +1,4 @@
-from ...helper import restricted_eval
+from tests.helper import restricted_eval
 
 
 def test_Or():
diff --git a/src/RestrictedPython/tests/transformer/operators/test_comparison_operators.py b/tests/transformer/operators/test_comparison_operators.py
similarity index 89%
rename from src/RestrictedPython/tests/transformer/operators/test_comparison_operators.py
rename to tests/transformer/operators/test_comparison_operators.py
index 8d8dc5e..7aa3e9a 100644
--- a/src/RestrictedPython/tests/transformer/operators/test_comparison_operators.py
+++ b/tests/transformer/operators/test_comparison_operators.py
@@ -1,4 +1,4 @@
-from ...helper import restricted_eval
+from tests.helper import restricted_eval
 
 
 def test_Eq():
diff --git a/src/RestrictedPython/tests/transformer/operators/test_identity_operators.py b/tests/transformer/operators/test_identity_operators.py
similarity index 77%
rename from src/RestrictedPython/tests/transformer/operators/test_identity_operators.py
rename to tests/transformer/operators/test_identity_operators.py
index 1707e73..ee9e9ca 100644
--- a/src/RestrictedPython/tests/transformer/operators/test_identity_operators.py
+++ b/tests/transformer/operators/test_identity_operators.py
@@ -1,4 +1,4 @@
-from ...helper import restricted_eval
+from tests.helper import restricted_eval
 
 
 def test_Is():
diff --git a/src/RestrictedPython/tests/transformer/operators/test_logical_operators.py b/tests/transformer/operators/test_logical_operators.py
similarity index 78%
rename from src/RestrictedPython/tests/transformer/operators/test_logical_operators.py
rename to tests/transformer/operators/test_logical_operators.py
index 5bc26d0..b4c585f 100644
--- a/src/RestrictedPython/tests/transformer/operators/test_logical_operators.py
+++ b/tests/transformer/operators/test_logical_operators.py
@@ -1,4 +1,4 @@
-from ...helper import restricted_eval
+from tests.helper import restricted_eval
 
 
 def test_In():
diff --git a/src/RestrictedPython/tests/transformer/operators/test_unary_operators.py b/tests/transformer/operators/test_unary_operators.py
similarity index 77%
rename from src/RestrictedPython/tests/transformer/operators/test_unary_operators.py
rename to tests/transformer/operators/test_unary_operators.py
index 83c585f..71d5492 100644
--- a/src/RestrictedPython/tests/transformer/operators/test_unary_operators.py
+++ b/tests/transformer/operators/test_unary_operators.py
@@ -1,4 +1,4 @@
-from ...helper import restricted_eval
+from tests.helper import restricted_eval
 
 
 def test_UAdd():
diff --git a/src/RestrictedPython/tests/transformer/test_assert.py b/tests/transformer/test_assert.py
similarity index 75%
rename from src/RestrictedPython/tests/transformer/test_assert.py
rename to tests/transformer/test_assert.py
index b747402..984cb89 100644
--- a/src/RestrictedPython/tests/transformer/test_assert.py
+++ b/tests/transformer/test_assert.py
@@ -1,4 +1,4 @@
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 def test_RestrictingNodeTransformer__visit_Assert__1():
diff --git a/src/RestrictedPython/tests/transformer/test_assign.py b/tests/transformer/test_assign.py
similarity index 96%
rename from src/RestrictedPython/tests/transformer/test_assign.py
rename to tests/transformer/test_assign.py
index 7ef9f32..c72fb37 100644
--- a/src/RestrictedPython/tests/transformer/test_assign.py
+++ b/tests/transformer/test_assign.py
@@ -1,6 +1,5 @@
 from RestrictedPython.Guards import guarded_unpack_sequence
-
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 def test_RestrictingNodeTransformer__visit_Assign__1(mocker):
diff --git a/src/RestrictedPython/tests/transformer/test_async.py b/tests/transformer/test_async.py
similarity index 100%
rename from src/RestrictedPython/tests/transformer/test_async.py
rename to tests/transformer/test_async.py
diff --git a/src/RestrictedPython/tests/transformer/test_attribute.py b/tests/transformer/test_attribute.py
similarity index 98%
rename from src/RestrictedPython/tests/transformer/test_attribute.py
rename to tests/transformer/test_attribute.py
index 5ca1432..1a6d239 100644
--- a/src/RestrictedPython/tests/transformer/test_attribute.py
+++ b/tests/transformer/test_attribute.py
@@ -1,6 +1,5 @@
 from RestrictedPython import compile_restricted_exec
-
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 BAD_ATTR_UNDERSCORE = """\
diff --git a/src/RestrictedPython/tests/transformer/test_augassign.py b/tests/transformer/test_augassign.py
similarity index 97%
rename from src/RestrictedPython/tests/transformer/test_augassign.py
rename to tests/transformer/test_augassign.py
index eb84144..3b78498 100644
--- a/src/RestrictedPython/tests/transformer/test_augassign.py
+++ b/tests/transformer/test_augassign.py
@@ -1,6 +1,5 @@
 from RestrictedPython import compile_restricted_exec
-
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 def test_RestrictingNodeTransformer__visit_AugAssign__1(
diff --git a/src/RestrictedPython/tests/transformer/test_base_types.py b/tests/transformer/test_base_types.py
similarity index 93%
rename from src/RestrictedPython/tests/transformer/test_base_types.py
rename to tests/transformer/test_base_types.py
index dcdcd88..a815f0f 100644
--- a/src/RestrictedPython/tests/transformer/test_base_types.py
+++ b/tests/transformer/test_base_types.py
@@ -1,6 +1,5 @@
 from RestrictedPython import compile_restricted_exec
-
-from ..helper import restricted_eval
+from tests.helper import restricted_eval
 
 
 def test_Num():
diff --git a/src/RestrictedPython/tests/transformer/test_breakpoint.py b/tests/transformer/test_breakpoint.py
similarity index 100%
rename from src/RestrictedPython/tests/transformer/test_breakpoint.py
rename to tests/transformer/test_breakpoint.py
diff --git a/src/RestrictedPython/tests/transformer/test_call.py b/tests/transformer/test_call.py
similarity index 98%
rename from src/RestrictedPython/tests/transformer/test_call.py
rename to tests/transformer/test_call.py
index 059bbf1..a44cf0b 100644
--- a/src/RestrictedPython/tests/transformer/test_call.py
+++ b/tests/transformer/test_call.py
@@ -1,6 +1,5 @@
 from RestrictedPython import compile_restricted_exec
-
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 def test_RestrictingNodeTransformer__visit_Call__1():
diff --git a/src/RestrictedPython/tests/transformer/test_classdef.py b/tests/transformer/test_classdef.py
similarity index 99%
rename from src/RestrictedPython/tests/transformer/test_classdef.py
rename to tests/transformer/test_classdef.py
index e5e1e83..8b370ab 100644
--- a/src/RestrictedPython/tests/transformer/test_classdef.py
+++ b/tests/transformer/test_classdef.py
@@ -1,7 +1,6 @@
 from RestrictedPython import compile_restricted_exec
 from RestrictedPython.Guards import safe_builtins
-
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 GOOD_CLASS = '''
diff --git a/src/RestrictedPython/tests/transformer/test_comparators.py b/tests/transformer/test_comparators.py
similarity index 98%
rename from src/RestrictedPython/tests/transformer/test_comparators.py
rename to tests/transformer/test_comparators.py
index 4e13fbb..26a00c7 100644
--- a/src/RestrictedPython/tests/transformer/test_comparators.py
+++ b/tests/transformer/test_comparators.py
@@ -1,4 +1,4 @@
-from ..helper import restricted_eval
+from tests.helper import restricted_eval
 
 
 def test_RestrictingNodeTransformer__visit_Eq__1():
diff --git a/src/RestrictedPython/tests/transformer/test_conditional.py b/tests/transformer/test_conditional.py
similarity index 95%
rename from src/RestrictedPython/tests/transformer/test_conditional.py
rename to tests/transformer/test_conditional.py
index ad56e13..6f222a4 100644
--- a/src/RestrictedPython/tests/transformer/test_conditional.py
+++ b/tests/transformer/test_conditional.py
@@ -1,4 +1,4 @@
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 def test_RestrictingNodeTransformer__test_ternary_if(
diff --git a/src/RestrictedPython/tests/transformer/test_dict_comprehension.py b/tests/transformer/test_dict_comprehension.py
similarity index 96%
rename from src/RestrictedPython/tests/transformer/test_dict_comprehension.py
rename to tests/transformer/test_dict_comprehension.py
index a414511..17b8c45 100644
--- a/src/RestrictedPython/tests/transformer/test_dict_comprehension.py
+++ b/tests/transformer/test_dict_comprehension.py
@@ -1,6 +1,5 @@
 from RestrictedPython._compat import IS_PY38_OR_GREATER
-
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 DICT_COMPREHENSION_WITH_ATTRS = """
diff --git a/src/RestrictedPython/tests/transformer/test_eval_exec.py b/tests/transformer/test_eval_exec.py
similarity index 100%
rename from src/RestrictedPython/tests/transformer/test_eval_exec.py
rename to tests/transformer/test_eval_exec.py
diff --git a/src/RestrictedPython/tests/transformer/test_fstring.py b/tests/transformer/test_fstring.py
similarity index 100%
rename from src/RestrictedPython/tests/transformer/test_fstring.py
rename to tests/transformer/test_fstring.py
index 68b1743..981026e 100644
--- a/src/RestrictedPython/tests/transformer/test_fstring.py
+++ b/tests/transformer/test_fstring.py
@@ -1,9 +1,9 @@
-import pytest
-
 from RestrictedPython import compile_restricted_exec
 from RestrictedPython._compat import IS_PY38_OR_GREATER
 from RestrictedPython.PrintCollector import PrintCollector
 
+import pytest
+
 
 def test_transform():
     """It compiles a function call successfully and returns the used name."""
diff --git a/src/RestrictedPython/tests/transformer/test_functiondef.py b/tests/transformer/test_functiondef.py
similarity index 99%
rename from src/RestrictedPython/tests/transformer/test_functiondef.py
rename to tests/transformer/test_functiondef.py
index 654b11d..17730f3 100644
--- a/src/RestrictedPython/tests/transformer/test_functiondef.py
+++ b/tests/transformer/test_functiondef.py
@@ -35,6 +35,7 @@ def test_RestrictingNodeTransformer__visit_FunctionDef__7():
     assert result.errors == (functiondef_err_msg,)
 
 
+
 BLACKLISTED_FUNC_NAMES_CALL_TEST = """
 def __init__(test):
     test
diff --git a/src/RestrictedPython/tests/transformer/test_generic.py b/tests/transformer/test_generic.py
similarity index 100%
rename from src/RestrictedPython/tests/transformer/test_generic.py
rename to tests/transformer/test_generic.py
index b0b748f..8ca41ce 100644
--- a/src/RestrictedPython/tests/transformer/test_generic.py
+++ b/tests/transformer/test_generic.py
@@ -1,7 +1,7 @@
-import ast
-
 from RestrictedPython import RestrictingNodeTransformer
 
+import ast
+
 
 def test_RestrictingNodeTransformer__generic_visit__1():
     """It log an error if there is an unknown ast node visited."""
diff --git a/src/RestrictedPython/tests/transformer/test_global_local.py b/tests/transformer/test_global_local.py
similarity index 94%
rename from src/RestrictedPython/tests/transformer/test_global_local.py
rename to tests/transformer/test_global_local.py
index dd4642a..3af01b4 100644
--- a/src/RestrictedPython/tests/transformer/test_global_local.py
+++ b/tests/transformer/test_global_local.py
@@ -1,6 +1,5 @@
 from RestrictedPython import compile_restricted_exec
-
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 GLOBAL_EXAMPLE = """
diff --git a/src/RestrictedPython/tests/transformer/test_import.py b/tests/transformer/test_import.py
similarity index 100%
rename from src/RestrictedPython/tests/transformer/test_import.py
rename to tests/transformer/test_import.py
diff --git a/src/RestrictedPython/tests/transformer/test_iterator.py b/tests/transformer/test_iterator.py
similarity index 98%
rename from src/RestrictedPython/tests/transformer/test_iterator.py
rename to tests/transformer/test_iterator.py
index 9e53ad0..bd593ab 100644
--- a/src/RestrictedPython/tests/transformer/test_iterator.py
+++ b/tests/transformer/test_iterator.py
@@ -1,8 +1,7 @@
-import types
-
 from RestrictedPython.Guards import guarded_iter_unpack_sequence
+from tests.helper import restricted_exec
 
-from ..helper import restricted_exec
+import types
 
 
 ITERATORS = """
diff --git a/src/RestrictedPython/tests/transformer/test_lambda.py b/tests/transformer/test_lambda.py
similarity index 97%
rename from src/RestrictedPython/tests/transformer/test_lambda.py
rename to tests/transformer/test_lambda.py
index b9428d5..2bf1f2e 100644
--- a/src/RestrictedPython/tests/transformer/test_lambda.py
+++ b/tests/transformer/test_lambda.py
@@ -1,6 +1,5 @@
 from RestrictedPython import compile_restricted_exec
-
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 lambda_err_msg = 'Line 1: "_bad" is an invalid variable ' \
diff --git a/src/RestrictedPython/tests/transformer/test_loop.py b/tests/transformer/test_loop.py
similarity index 94%
rename from src/RestrictedPython/tests/transformer/test_loop.py
rename to tests/transformer/test_loop.py
index a7777dd..971bff2 100644
--- a/src/RestrictedPython/tests/transformer/test_loop.py
+++ b/tests/transformer/test_loop.py
@@ -1,4 +1,4 @@
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 WHILE = """\
diff --git a/src/RestrictedPython/tests/transformer/test_name.py b/tests/transformer/test_name.py
similarity index 99%
rename from src/RestrictedPython/tests/transformer/test_name.py
rename to tests/transformer/test_name.py
index 493dd4c..e37d2d7 100644
--- a/src/RestrictedPython/tests/transformer/test_name.py
+++ b/tests/transformer/test_name.py
@@ -1,6 +1,5 @@
 from RestrictedPython import compile_restricted_exec
-
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 BAD_NAME_STARTING_WITH_UNDERSCORE = """\
diff --git a/src/RestrictedPython/tests/transformer/test_slice.py b/tests/transformer/test_slice.py
similarity index 94%
rename from src/RestrictedPython/tests/transformer/test_slice.py
rename to tests/transformer/test_slice.py
index b2220d2..f2eff38 100644
--- a/src/RestrictedPython/tests/transformer/test_slice.py
+++ b/tests/transformer/test_slice.py
@@ -1,6 +1,5 @@
 from operator import getitem
-
-from ..helper import restricted_eval
+from tests.helper import restricted_eval
 
 
 def test_slice():
diff --git a/src/RestrictedPython/tests/transformer/test_subscript.py b/tests/transformer/test_subscript.py
similarity index 99%
rename from src/RestrictedPython/tests/transformer/test_subscript.py
rename to tests/transformer/test_subscript.py
index b42edee..f774e1e 100644
--- a/src/RestrictedPython/tests/transformer/test_subscript.py
+++ b/tests/transformer/test_subscript.py
@@ -1,4 +1,4 @@
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 SIMPLE_SUBSCRIPTS = """
diff --git a/src/RestrictedPython/tests/transformer/test_try.py b/tests/transformer/test_try.py
similarity index 98%
rename from src/RestrictedPython/tests/transformer/test_try.py
rename to tests/transformer/test_try.py
index 9a4dae6..4abe400 100644
--- a/src/RestrictedPython/tests/transformer/test_try.py
+++ b/tests/transformer/test_try.py
@@ -1,6 +1,5 @@
 from RestrictedPython import compile_restricted_exec
-
-from ..helper import restricted_exec
+from tests.helper import restricted_exec
 
 
 TRY_EXCEPT = """
diff --git a/src/RestrictedPython/tests/transformer/test_with_stmt.py b/tests/transformer/test_with_stmt.py
similarity index 98%
rename from src/RestrictedPython/tests/transformer/test_with_stmt.py
rename to tests/transformer/test_with_stmt.py
index 7431729..57e440f 100644
--- a/src/RestrictedPython/tests/transformer/test_with_stmt.py
+++ b/tests/transformer/test_with_stmt.py
@@ -1,9 +1,8 @@
-import contextlib
-
 from RestrictedPython import compile_restricted_exec
 from RestrictedPython.Guards import guarded_unpack_sequence
+from tests.helper import restricted_exec
 
-from ..helper import restricted_exec
+import contextlib
 
 
 WITH_STMT_WITH_UNPACK_SEQUENCE = """
diff --git a/src/RestrictedPython/tests/transformer/test_yield.py b/tests/transformer/test_yield.py
similarity index 98%
rename from src/RestrictedPython/tests/transformer/test_yield.py
rename to tests/transformer/test_yield.py
index a85e603..33fb631 100644
--- a/src/RestrictedPython/tests/transformer/test_yield.py
+++ b/tests/transformer/test_yield.py
@@ -34,7 +34,7 @@ def test_yield_from():
     def my_external_generator():
         my_list = [1, 2, 3, 4, 5]
         for elem in my_list:
-            yield elem
+            yield(elem)
 
     local = {}
     exec(result.code, {}, local)
diff --git a/tox.ini b/tox.ini
index 315cb6f..9862d52 100644
--- a/tox.ini
+++ b/tox.ini
@@ -29,7 +29,7 @@ setenv =
 commands =
     python -V
     pip list
-    pytest --cov=src --cov-report= {posargs}
+    pytest --cov=src --cov=tests --cov-report= {posargs}
     sphinx-build -b doctest -d {envdir}/.cache/doctrees docs {envdir}/.cache/doctest
 extras =
     test
@@ -98,7 +98,7 @@ setenv =
     COVERAGE_FILE=.coverage
 commands =
     mkdir -p {toxinidir}/parts/htmlcov
-    pytest --cov=src --cov-report= {posargs}
+    pytest --cov=src --cov=tests --cov-report= {posargs}
     coverage run -a -m sphinx -b doctest -d {envdir}/.cache/doctrees docs {envdir}/.cache/doctest
     coverage html
     coverage report -m --fail-under=98.8