diff --git a/tests/test_immutable_sequence_view.py b/tests/test_immutable_sequence_view.py
index 5af7f5133..fd691798c 100644
--- a/tests/test_immutable_sequence_view.py
+++ b/tests/test_immutable_sequence_view.py
@@ -3,6 +3,7 @@ import pytest
 from typing import Sequence
 from textual._immutable_sequence_view import ImmutableSequenceView
 
+
 def wrap(source: Sequence[int]) -> ImmutableSequenceView[int]:
     """Wrap a sequence of integers inside an immutable sequence view."""
     return ImmutableSequenceView[int](source)
@@ -24,7 +25,7 @@ def test_non_empty_immutable_sequence() -> None:
 
 def test_no_assign_to_immutable_sequence() -> None:
     """It should not be possible to assign into an immutable sequence."""
-    tester = wrap([1,2,3,4,5])
+    tester = wrap([1, 2, 3, 4, 5])
     with pytest.raises(TypeError):
         tester[0] = 23
     with pytest.raises(TypeError):
@@ -33,7 +34,7 @@ def test_no_assign_to_immutable_sequence() -> None:
 
 def test_no_del_from_iummutable_sequence() -> None:
     """It should not be possible delete an item from an immutable sequence."""
-    tester = wrap([1,2,3,4,5])
+    tester = wrap([1, 2, 3, 4, 5])
     with pytest.raises(TypeError):
         del tester[0]
 
@@ -46,23 +47,23 @@ def test_get_item_from_immutable_sequence() -> None:
 
 def test_get_slice_from_immutable_sequence() -> None:
     """It should be possible to get a slice from an immutable sequence."""
-    assert list(wrap(range(10))[0:2]) == [0,1]
-    assert list(wrap(range(10))[0:-1]) == [0,1,2,3,4,5,6,7,8]
+    assert list(wrap(range(10))[0:2]) == [0, 1]
+    assert list(wrap(range(10))[0:-1]) == [0, 1, 2, 3, 4, 5, 6, 7, 8]
 
 
 def test_immutable_sequence_contains() -> None:
     """It should be possible to see if an immutable sequence contains a value."""
-    tester = wrap([1,2,3,4,5])
+    tester = wrap([1, 2, 3, 4, 5])
     assert 1 in tester
     assert 11 not in tester
 
 
 def test_immutable_sequence_index() -> None:
-    tester = wrap([1,2,3,4,5])
+    tester = wrap([1, 2, 3, 4, 5])
     assert tester.index(1) == 0
     with pytest.raises(ValueError):
         _ = tester.index(11)
 
 
 def test_reverse_immutable_sequence() -> None:
-    assert list(reversed(wrap([1,2]))) == [2,1]
+    assert list(reversed(wrap([1, 2]))) == [2, 1]