diff --git a/setup.py b/setup.py
index 4fe4839..656319f 100644
--- a/setup.py
+++ b/setup.py
@@ -3,7 +3,7 @@
 
 setup(
     name='py-vkontakte',
-    version='5.69.1',
+    version='5.69.2',
     packages=['vk'],
     url='https://github.com/sgaynetdinov/py-vkontakte',
     license='MIT License',
diff --git a/tests/test_group.py b/tests/test_group.py
index 430ef69..c04df11 100644
--- a/tests/test_group.py
+++ b/tests/test_group.py
@@ -1,6 +1,9 @@
+from unittest.mock import patch
+
 import pytest
 
 from vk.groups import Group
+from vk.users import User
 
 
 def test_detail(factory):
@@ -13,3 +16,25 @@ def test_detail(factory):
     assert group.type == 'group'
     assert group.is_trending == False
 
+
+@pytest.mark.parametrize("user", [
+    "100500",
+    100500.0,
+])
+def test_contains_fail(factory, user):
+    group = Group.from_json(None, factory('group_detail.json'))
+
+    with pytest.raises(TypeError, match="is not `User`"):
+        user in group
+
+
+@pytest.mark.parametrize("user", [
+    User.from_json(None, {"id": 100500}),
+    100500,
+])
+def test_contains(factory, user):
+    session = type("", (object,), {"fetch": lambda *args, **kw: True})
+    group = Group.from_json(session, factory('group_detail.json'))
+
+    assert user in group
+
diff --git a/vk/groups.py b/vk/groups.py
index 370c342..2a3eb5b 100644
--- a/vk/groups.py
+++ b/vk/groups.py
@@ -113,7 +113,9 @@ def __contains__(self, user_instance):
         """
         https://vk.com/dev/groups.isMember
         """
-        if not isinstance(user_instance, User):
+        if not isinstance(user_instance, (int, User)):
             raise TypeError("object {0} is not `User`".format(user_instance))
 
-        return bool(self._session.fetch("groups.isMember", group_id=self.id, user_id=user_instance.id))
+        user_id = user_instance.id if hasattr(user_instance, "id") else user_instance
+
+        return bool(self._session.fetch("groups.isMember", group_id=self.id, user_id=user_id))