diff --git a/setup.py b/setup.py
index 239d7b0..abae423 100755
--- a/setup.py
+++ b/setup.py
@@ -33,7 +33,7 @@
 are valid.
 """,
     license="LGPLv2+",
-    version="2.1.1",
+    version="2.1.2",
     author="Viktor Hercinger",
     author_email="viktor.hercinger@balabit.com",
     maintainer="Viktor Hercinger",
@@ -68,6 +68,5 @@
     install_requires=[
         'nose',
         'sphinx',
-        'typing_inspect',
     ]
 )
diff --git a/tox.ini b/tox.ini
index 39b318d..ecc8ab4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -12,7 +12,6 @@ deps=
   behave
 
   coverage
-  typing_inspect
   py34: typing
 
 commands=
diff --git a/typesafety/tests/test_typing_inspect.py b/typesafety/tests/test_typing_inspect.py
new file mode 100644
index 0000000..556d145
--- /dev/null
+++ b/typesafety/tests/test_typing_inspect.py
@@ -0,0 +1,37 @@
+#
+# Copyright (c) 2013-2018 Balabit
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#
+
+import typing
+import unittest
+
+from typesafety.typing_inspect import is_union_type, get_union_args
+
+
+class TestTypingInspect(unittest.TestCase):
+    def test_inspect_union_type(self):
+        self.assertTrue(is_union_type(typing.Union))
+        self.assertTrue(is_union_type(typing.Union[int, str]))
+        self.assertTrue(is_union_type(typing.Optional[int]))
+        self.assertFalse(is_union_type(typing.List[int]))
+        self.assertFalse(is_union_type(typing.Any))
+
+    def test_get_union_args(self):
+        self.assertEqual((), get_union_args(typing.Union))
+        self.assertEqual((int, str), get_union_args(typing.Union[int, str]))
+        self.assertEqual((int, type(None)), get_union_args(typing.Optional[int]))
+        self.assertRaises(TypeError, get_union_args, typing.List[int])
+        self.assertRaises(TypeError, get_union_args, typing.Any)
diff --git a/typesafety/typing_inspect.py b/typesafety/typing_inspect.py
new file mode 100644
index 0000000..d13fc45
--- /dev/null
+++ b/typesafety/typing_inspect.py
@@ -0,0 +1,51 @@
+#
+# Copyright (c) 2013-2018 Balabit
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#
+
+'''
+This module contains helper methods for dealing with the contents of the typing module. This
+module is not really stable so there are differences even between minor versions. See:
+
+    https://docs.python.org/3.6/library/typing.html
+
+Note that this module is flaky and very hacky, but hopefully later we can use some external
+tool for this.
+'''
+
+# There is no good, idiomatic way to determine if an annotation is a union or not,
+# so we're saddled with this hacky solution.
+# pylint: disable=unidiomatic-typecheck,protected-access
+import typing
+
+
+def is_union_type(cls):
+    if hasattr(typing, '_Union'):
+        return type(cls) is typing._Union
+
+    return type(cls) is typing.UnionMeta
+
+
+def get_union_args(cls):
+    if not is_union_type(cls):
+        raise TypeError('expected union type')
+
+    if hasattr(cls, '__args__'):
+        res = cls.__args__
+
+    else:
+        res = cls.__union_params__
+
+    return res if res is not None else ()
diff --git a/typesafety/validator.py b/typesafety/validator.py
index bfd38f3..94dffad 100644
--- a/typesafety/validator.py
+++ b/typesafety/validator.py
@@ -19,7 +19,7 @@
 import inspect
 import warnings
 
-from typing_inspect import is_union_type, get_args
+from typesafety.typing_inspect import is_union_type, get_union_args
 
 
 class TypesafetyError(Exception):
@@ -174,6 +174,9 @@ def validate_arguments(self, locals_dict):
                 raise TypesafetyError(message)
 
     def __format_expectation(self, annotation):
+        if is_union_type(annotation):
+            return 'typing.Union[{}]'.format(', '.join(entry.__name__ for entry in get_union_args(annotation)))
+
         if isinstance(annotation, tuple):
             return "({})".format(
                 ", ".join(self.__format_expectation(a) for a in annotation)
@@ -278,7 +281,7 @@ def __is_valid(self, value, validator):
         if is_union_type(validator):
             return any(
                 self.__is_valid(value, subvalidator)
-                for subvalidator in get_args(validator)
+                for subvalidator in get_union_args(validator)
             )
 
         if isinstance(validator, type):
@@ -307,7 +310,7 @@ def __is_valid_typecheck_annotation(self, validator):
         if is_union_type(validator):
             return all(
                 self.__is_valid_typecheck_annotation(subvalidator)
-                for subvalidator in get_args(validator)
+                for subvalidator in get_union_args(validator)
             )
 
         if isinstance(validator, type):