diff --git a/Tests/test_util.py b/Tests/test_util.py
index 197ef79ee..9eaabf18a 100644
--- a/Tests/test_util.py
+++ b/Tests/test_util.py
@@ -30,28 +30,6 @@ def test_is_not_path(tmp_path: Path) -> None:
     assert not it_is_not
 
 
-def test_is_directory() -> None:
-    # Arrange
-    directory = "Tests"
-
-    # Act
-    it_is = _util.is_directory(directory)
-
-    # Assert
-    assert it_is
-
-
-def test_is_not_directory() -> None:
-    # Arrange
-    text = "abc"
-
-    # Act
-    it_is_not = _util.is_directory(text)
-
-    # Assert
-    assert not it_is_not
-
-
 def test_deferred_error() -> None:
     # Arrange
 
diff --git a/src/PIL/_util.py b/src/PIL/_util.py
index 6bc762816..8ef0d36f7 100644
--- a/src/PIL/_util.py
+++ b/src/PIL/_util.py
@@ -10,11 +10,6 @@ def is_path(f: Any) -> TypeGuard[StrOrBytesPath]:
     return isinstance(f, (bytes, str, os.PathLike))
 
 
-def is_directory(f: Any) -> TypeGuard[StrOrBytesPath]:
-    """Checks if an object is a string, and that it points to a directory."""
-    return is_path(f) and os.path.isdir(f)
-
-
 class DeferredError:
     def __init__(self, ex: BaseException):
         self.ex = ex