@@ -9,7 +9,7 @@
 
 # typing ----------------------------------------------------------------------
 
-from typing import NamedTuple, Sequence, TYPE_CHECKING, Tuple, Union, cast
+from typing import NamedTuple, Sequence, TYPE_CHECKING, Tuple, Union, cast, List
 
 from git.types import PathLike
 
@@ -57,7 +57,11 @@ def __call__(self, stage_blob: Tuple[StageType, Blob]) -> bool:
         for pathlike in self.paths:
             path: Path = pathlike if isinstance(pathlike, Path) else Path(pathlike)
             # TODO: Change to use `PosixPath.is_relative_to` once Python 3.8 is no longer supported.
-            if all(i == j for i, j in zip(path.parts, blob_path.parts)):
+            filter_parts: List[str] = path.parts
+            blob_parts: List[str] = blob_path.parts
+            if len(filter_parts) > len(blob_parts):
+                continue
+            if all(i == j for i, j in zip(filter_parts, blob_parts)):
                 return True
         return False
 
 
@@ -0,0 +1,31 @@
+"""Test the blob filter."""
+from pathlib import Path
+from typing import Sequence, Tuple
+from unittest.mock import MagicMock
+
+import pytest
+
+from git.index.typ import BlobFilter, StageType
+from git.objects import Blob
+from git.types import PathLike
+
+
+# fmt: off
+@pytest.mark.parametrize('paths, stage_type, path, expected_result', [
+    ((Path("foo"),), 0, Path("foo"), True),
+    ((Path("foo"),), 0, Path("foo/bar"), True),
+    ((Path("foo/bar"),), 0, Path("foo"), False),
+    ((Path("foo"), Path("bar")), 0, Path("foo"), True),
+])
+# fmt: on
+def test_blob_filter(paths: Sequence[PathLike], stage_type: StageType, path: PathLike, expected_result: bool) -> None:
+    """Test the blob filter."""
+    blob_filter = BlobFilter(paths)
+
+    binsha = MagicMock(__len__=lambda self: 20)
+    blob: Blob = Blob(repo=MagicMock(), binsha=binsha, path=path)
+    stage_blob: Tuple[StageType, Blob] = (stage_type, blob)
+
+    result = blob_filter(stage_blob)
+
+    assert result == expected_result