diff --git a/Libraries/PyKotor/tests/diff_tool/test_cli_utils.py b/Libraries/PyKotor/tests/diff_tool/test_cli_utils.py
new file mode 100644
index 000000000..9229b4f5c
--- /dev/null
+++ b/Libraries/PyKotor/tests/diff_tool/test_cli_utils.py
@@ -0,0 +1,56 @@
+"""Regression tests for diff_tool CLI path normalization and install detection."""
+
+from __future__ import annotations
+
+import json
+import sys
+from pathlib import Path
+
+import pytest
+
+from pykotor.diff_tool.cli_utils import is_kotor_install_dir, normalize_path_arg
+
+
+@pytest.mark.parametrize(
+    ("raw", "expected"),
+    [
+        (None, None),
+        ("", None),
+        ("   ", None),
+        ('"C:\\Games\\KOTOR"', r"C:\Games\KOTOR"),
+        ("'C:/Games/KOTOR'", "C:/Games/KOTOR"),
+        (r'C:\Program Files\Steam" C:\other', r"C:\Program Files\Steam"),
+        (r'C:\Program Files\folder\\', r"C:\Program Files\folder"),
+        ("C:/folder/", "C:/folder"),
+    ],
+)
+def test_normalize_path_arg(raw: str | None, expected: str | None) -> None:
+    assert normalize_path_arg(raw) == expected
+
+
+def test_is_kotor_install_dir_false_when_not_directory(tmp_path: Path) -> None:
+    key_file = tmp_path / "chitin.key"
+    key_file.write_bytes(b"")
+    assert is_kotor_install_dir(key_file) is False
+
+
+def test_is_kotor_install_dir_false_without_chitin(tmp_path: Path) -> None:
+    assert is_kotor_install_dir(tmp_path) is False
+
+
+def test_is_kotor_install_dir_true_with_chitin_key(tmp_path: Path) -> None:
+    (tmp_path / "chitin.key").write_bytes(b"")
+    assert is_kotor_install_dir(tmp_path) is True
+
+
+@pytest.mark.skipif(
+    sys.platform == "win32",
+    reason="Case-mismatch path semantics differ on Windows filesystems.",
+)
+def test_is_kotor_install_dir_case_mismatched_chitin_key(tmp_path: Path) -> None:
+    install_dir = tmp_path / "GameRoot"
+    install_dir.mkdir()
+    (install_dir / "chitin.key").write_bytes(b"")
+
+    mismatched = tmp_path / "gameroot"
+    assert is_kotor_install_dir(mismatched) is True
diff --git a/Libraries/PyKotor/tests/test_indoorkit_case_path.py b/Libraries/PyKotor/tests/test_indoorkit_case_path.py
new file mode 100644
index 000000000..f920b53be
--- /dev/null
+++ b/Libraries/PyKotor/tests/test_indoorkit_case_path.py
@@ -0,0 +1,29 @@
+"""Regression tests for CaseAwarePath usage in indoor kit loading (PR #151)."""
+
+from __future__ import annotations
+
+import json
+import sys
+from pathlib import Path
+
+import pytest
+
+from pykotor.tools.indoorkit import load_kits_unified
+
+
+@pytest.mark.skipif(
+    sys.platform == "win32",
+    reason="Case-mismatch path semantics differ on Windows filesystems.",
+)
+def test_load_kits_unified_case_mismatched_kits_directory(tmp_path: Path) -> None:
+    kits_dir = tmp_path / "MyKits"
+    kits_dir.mkdir()
+    v1 = {"name": "Legacy", "id": "legacy", "doors": [], "components": []}
+    (kits_dir / "legacy.json").write_text(json.dumps(v1), encoding="utf-8")
+
+    mismatched_path = tmp_path / "mykits"
+    kits, tile_kits = load_kits_unified(mismatched_path)
+
+    assert len(kits) == 1
+    assert kits[0].id == "legacy"
+    assert tile_kits == []