diff --git a/tests/units/tokens/test_timeout_token.py b/tests/units/tokens/test_timeout_token.py
index 15549c5..a5dfe75 100644
--- a/tests/units/tokens/test_timeout_token.py
+++ b/tests/units/tokens/test_timeout_token.py
@@ -329,3 +329,377 @@ def test_timeout_is_more_important_than_cache():
 def test_zero_timeout_token_report_is_about_superpower():
     for report in TimeoutToken(0).get_report(True), TimeoutToken(0).get_report(False):
         assert report.cause == CancelCause.SUPERPOWER
+
+
+@pytest.mark.parametrize(
+    ['addictional_kwargs'],
+    [
+        ({'monotonic': False},),
+        ({},),
+        ({'monotonic': True},),
+    ],
+)
+def test_bigger_temp_timeout_token_plus_less_temp_timeout_token_with_same_monotonic_flag(addictional_kwargs):
+    token = TimeoutToken(2, **addictional_kwargs) + TimeoutToken(1, **addictional_kwargs)
+
+    assert isinstance(token, TimeoutToken)
+    assert token.timeout == 2
+    assert len(token.tokens) == 1
+    assert len(token.tokens[0].tokens) == 0
+    assert isinstance(token.tokens[0], TimeoutToken)
+    assert token.tokens[0].timeout == 1
+
+
+@pytest.mark.parametrize(
+    ['left_addictional_kwargs', 'right_addictional_kwargs'],
+    [
+        ({'monotonic': False}, {'monotonic': True}),
+        ({}, {'monotonic': True}),
+        ({'monotonic': True}, {'monotonic': False}),
+        ({'monotonic': True}, {}),
+    ],
+)
+def test_bigger_temp_timeout_token_plus_less_temp_timeout_token_with_not_same_monotonic_flag(left_addictional_kwargs, right_addictional_kwargs):
+    token = TimeoutToken(2, **left_addictional_kwargs) + TimeoutToken(1, **right_addictional_kwargs)
+
+    assert isinstance(token, TimeoutToken)
+    assert token.timeout == 2
+    assert len(token.tokens) == 1
+    assert len(token.tokens[0].tokens) == 0
+    assert isinstance(token.tokens[0], TimeoutToken)
+    assert token.tokens[0].timeout == 1
+
+
+@pytest.mark.parametrize(
+    ['timeout_for_equal_or_bigger_token'],
+    [
+        (1,),
+        (2,),
+    ],
+)
+@pytest.mark.parametrize(
+    ['addictional_kwargs'],
+    [
+        ({'monotonic': False},),
+        ({},),
+        ({'monotonic': True},),
+    ],
+)
+def test_less_or_equal_temp_not_monotonic_timeout_token_plus_bigger_or_equal_temp_not_monotonic_timeout_token_with_same_monotonic_flag(timeout_for_equal_or_bigger_token, addictional_kwargs):
+    token = TimeoutToken(1, **addictional_kwargs) + TimeoutToken(timeout_for_equal_or_bigger_token, **addictional_kwargs)
+
+    assert isinstance(token, TimeoutToken)
+    assert token.timeout == 1
+    assert len(token.tokens) == 0
+
+
+@pytest.mark.parametrize(
+    ['timeout_for_equal_or_bigger_token'],
+    [
+        (1,),
+        (2,),
+    ],
+)
+@pytest.mark.parametrize(
+    ['left_addictional_kwargs', 'right_addictional_kwargs'],
+    [
+        ({'monotonic': False}, {'monotonic': True}),
+        ({}, {'monotonic': True}),
+        ({'monotonic': True}, {'monotonic': False}),
+        ({'monotonic': True}, {}),
+    ],
+)
+def test_less_or_equal_temp_not_monotonic_timeout_token_plus_bigger_or_equal_temp_not_monotonic_timeout_token_with_not_same_monotonic_flag(timeout_for_equal_or_bigger_token, left_addictional_kwargs, right_addictional_kwargs):
+    token = TimeoutToken(1, **left_addictional_kwargs) + TimeoutToken(timeout_for_equal_or_bigger_token, **right_addictional_kwargs)
+
+    assert isinstance(token, TimeoutToken)
+    assert token.timeout == 1
+    assert len(token.tokens) == 1
+    assert len(token.tokens[0].tokens) == 0
+    assert isinstance(token.tokens[0], TimeoutToken)
+    assert token.tokens[0].timeout == timeout_for_equal_or_bigger_token
+
+
+@pytest.mark.parametrize(
+    ['addictional_kwargs'],
+    [
+        ({'monotonic': False},),
+        ({},),
+        ({'monotonic': True},),
+    ],
+)
+def test_bigger_timeout_token_plus_less_temp_timeout_token_with_same_monotonic_flag(addictional_kwargs):
+    left_timeout_token = TimeoutToken(2, **addictional_kwargs)
+    token = left_timeout_token + TimeoutToken(1, **addictional_kwargs)
+
+    assert isinstance(token, TimeoutToken)
+    assert token is not left_timeout_token
+    assert token.timeout == 1
+    assert len(token.tokens) == 0
+
+
+@pytest.mark.parametrize(
+    ['left_addictional_kwargs', 'right_addictional_kwargs'],
+    [
+        ({'monotonic': False}, {'monotonic': True}),
+        ({}, {'monotonic': True}),
+        ({'monotonic': True}, {'monotonic': False}),
+        ({'monotonic': True}, {}),
+    ],
+)
+def test_bigger_timeout_token_plus_less_temp_timeout_token_with_not_same_monotonic_flag(left_addictional_kwargs, right_addictional_kwargs):
+    left_timeout_token = TimeoutToken(2, **left_addictional_kwargs)
+    token = left_timeout_token + TimeoutToken(1, **right_addictional_kwargs)
+
+    assert isinstance(token, TimeoutToken)
+    assert token.timeout == 1
+    assert len(token.tokens) == 1
+    assert len(token.tokens[0].tokens) == 0
+    assert isinstance(token.tokens[0], TimeoutToken)
+    assert token.tokens[0].timeout == 2
+    assert token.tokens[0] is left_timeout_token
+
+
+@pytest.mark.parametrize(
+    ['addictional_kwargs'],
+    [
+        ({'monotonic': False},),
+        ({},),
+        ({'monotonic': True},),
+    ],
+)
+def test_less_not_monotonic_timeout_token_plus_bigger_temp_not_monotonic_timeout_token_with_same_monotonic_flag(addictional_kwargs):
+    left_timeout_token = TimeoutToken(1, **addictional_kwargs)
+    token = left_timeout_token + TimeoutToken(2, **addictional_kwargs)
+
+    assert isinstance(token, TimeoutToken)
+    assert token.timeout == 2
+    assert len(token.tokens) == 1
+    assert len(token.tokens[0].tokens) == 0
+    assert isinstance(token.tokens[0], TimeoutToken)
+    assert token.tokens[0].timeout == 1
+    assert token.tokens[0] is left_timeout_token
+
+
+@pytest.mark.parametrize(
+    ['left_addictional_kwargs', 'right_addictional_kwargs'],
+    [
+        ({'monotonic': False}, {'monotonic': True}),
+        ({}, {'monotonic': True}),
+        ({'monotonic': True}, {'monotonic': False}),
+        ({'monotonic': True}, {}),
+    ],
+)
+def test_less_not_monotonic_timeout_token_plus_bigger_temp_not_monotonic_timeout_token_with_not_same_monotonic_flag(left_addictional_kwargs, right_addictional_kwargs):
+    left_timeout_token = TimeoutToken(1, **left_addictional_kwargs)
+    token = left_timeout_token + TimeoutToken(2, **right_addictional_kwargs)
+
+    assert isinstance(token, TimeoutToken)
+    assert token.timeout == 2
+    assert len(token.tokens) == 1
+    assert len(token.tokens[0].tokens) == 0
+    assert isinstance(token.tokens[0], TimeoutToken)
+    assert token.tokens[0].timeout == 1
+    assert token.tokens[0] is left_timeout_token
+
+
+@pytest.mark.parametrize(
+    ['addictional_kwargs'],
+    [
+        ({'monotonic': False},),
+        ({},),
+        ({'monotonic': True},),
+    ],
+)
+def test_bigger_temp_timeout_token_plus_less_timeout_token_with_same_monotonic_flag(addictional_kwargs):
+    right_timeout_token = TimeoutToken(1, **addictional_kwargs)
+    token = TimeoutToken(2, **addictional_kwargs) + right_timeout_token
+
+    assert isinstance(token, TimeoutToken)
+    assert token.timeout == 2
+    assert len(token.tokens) == 1
+    assert len(token.tokens[0].tokens) == 0
+    assert isinstance(token.tokens[0], TimeoutToken)
+    assert token.tokens[0].timeout == 1
+    assert token.tokens[0] is right_timeout_token
+
+
+@pytest.mark.parametrize(
+    ['left_addictional_kwargs', 'right_addictional_kwargs'],
+    [
+        ({'monotonic': False}, {'monotonic': True}),
+        ({}, {'monotonic': True}),
+        ({'monotonic': True}, {'monotonic': False}),
+        ({'monotonic': True}, {}),
+    ],
+)
+def test_bigger_temp_timeout_token_plus_less_timeout_token_with_not_same_monotonic_flag(left_addictional_kwargs, right_addictional_kwargs):
+    right_timeout_token = TimeoutToken(1, **right_addictional_kwargs)
+    token = TimeoutToken(2, **left_addictional_kwargs) + right_timeout_token
+
+    assert isinstance(token, TimeoutToken)
+    assert token.timeout == 2
+    assert len(token.tokens) == 1
+    assert len(token.tokens[0].tokens) == 0
+    assert isinstance(token.tokens[0], TimeoutToken)
+    assert token.tokens[0].timeout == 1
+    assert token.tokens[0] is right_timeout_token
+
+
+@pytest.mark.parametrize(
+    ['addictional_kwargs'],
+    [
+        ({'monotonic': False},),
+        ({},),
+        ({'monotonic': True},),
+    ],
+)
+def test_less_temp_not_monotonic_timeout_token_plus_bigger_not_monotonic_timeout_token_with_same_monotonic_flag(addictional_kwargs):
+    right_timeout_token = TimeoutToken(2, **addictional_kwargs)
+    token = TimeoutToken(1, **addictional_kwargs) + right_timeout_token
+
+    assert isinstance(token, TimeoutToken)
+    assert token.timeout == 1
+    assert len(token.tokens) == 0
+
+
+@pytest.mark.parametrize(
+    ['left_addictional_kwargs', 'right_addictional_kwargs'],
+    [
+        ({'monotonic': False}, {'monotonic': True}),
+        ({}, {'monotonic': True}),
+        ({'monotonic': True}, {'monotonic': False}),
+        ({'monotonic': True}, {}),
+    ],
+)
+def test_less_temp_not_monotonic_timeout_token_plus_bigger_not_monotonic_timeout_token_with_not_same_monotonic_flag(left_addictional_kwargs, right_addictional_kwargs):
+    right_timeout_token = TimeoutToken(2, **right_addictional_kwargs)
+    token = TimeoutToken(1, **left_addictional_kwargs) + right_timeout_token
+
+    assert isinstance(token, TimeoutToken)
+    assert token.timeout == 1
+    assert len(token.tokens) == 1
+    assert len(token.tokens[0].tokens) == 0
+    assert isinstance(token.tokens[0], TimeoutToken)
+    assert token.tokens[0].timeout == 2
+    assert token.tokens[0] is right_timeout_token
+
+
+@pytest.mark.parametrize(
+    ['addictional_kwargs'],
+    [
+        ({'monotonic': False},),
+        ({},),
+        ({'monotonic': True},),
+    ],
+)
+def test_bigger_timeout_token_plus_less_timeout_token_with_same_monotonic_flag(addictional_kwargs):
+    left = TimeoutToken(2, **addictional_kwargs)
+    right = TimeoutToken(1, **addictional_kwargs)
+    token = left + right
+
+    assert isinstance(token, SimpleToken)
+    assert token
+    assert len(token.tokens) == 2
+    assert len(token.tokens[0].tokens) == 0
+    assert len(token.tokens[1].tokens) == 0
+    assert isinstance(token.tokens[0], TimeoutToken)
+    assert isinstance(token.tokens[1], TimeoutToken)
+    assert token.tokens[0].timeout == 2
+    assert token.tokens[1].timeout == 1
+    assert token.tokens[0] is left
+    assert token.tokens[1] is right
+
+
+@pytest.mark.parametrize(
+    ['left_addictional_kwargs', 'right_addictional_kwargs'],
+    [
+        ({'monotonic': False}, {'monotonic': True}),
+        ({}, {'monotonic': True}),
+        ({'monotonic': True}, {'monotonic': False}),
+        ({'monotonic': True}, {}),
+    ],
+)
+def test_bigger_timeout_token_plus_less_timeout_token_with_not_same_monotonic_flag(left_addictional_kwargs, right_addictional_kwargs):
+    left = TimeoutToken(2, **left_addictional_kwargs)
+    right = TimeoutToken(1, **right_addictional_kwargs)
+    token = left + right
+
+    assert isinstance(token, SimpleToken)
+    assert token
+    assert len(token.tokens) == 2
+    assert len(token.tokens[0].tokens) == 0
+    assert len(token.tokens[1].tokens) == 0
+    assert isinstance(token.tokens[0], TimeoutToken)
+    assert isinstance(token.tokens[1], TimeoutToken)
+    assert token.tokens[0].timeout == 2
+    assert token.tokens[1].timeout == 1
+    assert token.tokens[0] is left
+    assert token.tokens[1] is right
+
+
+@pytest.mark.parametrize(
+    ['timeout_for_equal_or_bigger_token'],
+    [
+        (1,),
+        (2,),
+    ],
+)
+@pytest.mark.parametrize(
+    ['addictional_kwargs'],
+    [
+        ({'monotonic': False},),
+        ({},),
+        ({'monotonic': True},),
+    ],
+)
+def test_less_or_equal_not_monotonic_timeout_token_plus_bigger_or_equal_not_monotonic_timeout_token_with_same_monotonic_flag(timeout_for_equal_or_bigger_token, addictional_kwargs):
+    left = TimeoutToken(1, **addictional_kwargs)
+    right = TimeoutToken(timeout_for_equal_or_bigger_token, **addictional_kwargs)
+    token = left + right
+
+    assert isinstance(token, SimpleToken)
+    assert token
+    assert len(token.tokens) == 2
+    assert len(token.tokens[0].tokens) == 0
+    assert len(token.tokens[1].tokens) == 0
+    assert isinstance(token.tokens[0], TimeoutToken)
+    assert isinstance(token.tokens[1], TimeoutToken)
+    assert token.tokens[0].timeout == 1
+    assert token.tokens[1].timeout == timeout_for_equal_or_bigger_token
+    assert token.tokens[0] is left
+    assert token.tokens[1] is right
+
+
+@pytest.mark.parametrize(
+    ['timeout_for_equal_or_bigger_token'],
+    [
+        (1,),
+        (2,),
+    ],
+)
+@pytest.mark.parametrize(
+    ['left_addictional_kwargs', 'right_addictional_kwargs'],
+    [
+        ({'monotonic': False}, {'monotonic': True}),
+        ({}, {'monotonic': True}),
+        ({'monotonic': True}, {'monotonic': False}),
+        ({'monotonic': True}, {}),
+    ],
+)
+def test_less_or_equal_not_monotonic_timeout_token_plus_bigger_or_equal_not_monotonic_timeout_token_with_not_same_monotonic_flag(timeout_for_equal_or_bigger_token, left_addictional_kwargs, right_addictional_kwargs):
+    left = TimeoutToken(1, **left_addictional_kwargs)
+    right = TimeoutToken(timeout_for_equal_or_bigger_token, **right_addictional_kwargs)
+    token = left + right
+
+    assert isinstance(token, SimpleToken)
+    assert token
+    assert len(token.tokens) == 2
+    assert len(token.tokens[0].tokens) == 0
+    assert len(token.tokens[1].tokens) == 0
+    assert isinstance(token.tokens[0], TimeoutToken)
+    assert isinstance(token.tokens[1], TimeoutToken)
+    assert token.tokens[0].timeout == 1
+    assert token.tokens[1].timeout == timeout_for_equal_or_bigger_token
+    assert token.tokens[0] is left
+    assert token.tokens[1] is right