diff --git a/gitignorefile/__init__.py b/gitignorefile/__init__.py
index 31bf1fd..e7db8e3 100644
--- a/gitignorefile/__init__.py
+++ b/gitignorefile/__init__.py
@@ -31,32 +31,17 @@ class Cache:
     def __init__(self):
         self.__gitignores = {}
 
-    def __get_parents(self, path, is_dir):
-        if not is_dir:
-            path = os.path.dirname(path)
-            yield path
-
-        while True:
-            new_path = os.path.dirname(path)
-            if not os.path.samefile(path, new_path):
-                yield new_path
-                path = new_path
-            else:
-                break
-
     def __call__(self, path, is_dir=None):
-        if is_dir is None:
-            is_dir = os.path.isdir(path)
-
+        path = _Path(path)
         add_to_children = {}
         plain_paths = []
-        for parent in self.__get_parents(os.path.abspath(path), is_dir=is_dir):
-            if parent in self.__gitignores:
+        for parent in path.parents():
+            if parent.parts in self.__gitignores:
                 break
 
-            parent_gitignore = os.path.join(parent, ".gitignore")
-            if os.path.isfile(parent_gitignore):
-                p = parse(parent_gitignore, base_path=parent)
+            parent_gitignore = parent.join(".gitignore")
+            if parent_gitignore.isfile():
+                p = parse(str(parent_gitignore), base_path=parent)
                 add_to_children[parent] = (p, plain_paths)
                 plain_paths = []
 
@@ -71,21 +56,68 @@ def __call__(self, path, is_dir=None):
                 return False
 
         for parent, (_, parent_plain_paths) in reversed(list(add_to_children.items())):
-            self.__gitignores[parent] = []
+            self.__gitignores[parent.parts] = []
             for parent_to_add, (gitignore_to_add, _) in reversed(list(add_to_children.items())):
-                self.__gitignores[parent].append(gitignore_to_add)
+                self.__gitignores[parent.parts].append(gitignore_to_add)
                 if parent_to_add == parent:
                     break
 
-            self.__gitignores[parent].reverse()
+            self.__gitignores[parent.parts].reverse()
             for plain_path in parent_plain_paths:
-                self.__gitignores[plain_path] = self.__gitignores[parent]
+                self.__gitignores[plain_path.parts] = self.__gitignores[parent.parts]
 
         return any(
-            (m(path, is_dir=is_dir) for m in self.__gitignores[parent])
+            (m(path, is_dir=is_dir) for m in self.__gitignores[parent.parts])
         )  # This parent comes either from first or second loop.
 
 
+class _Path:
+    def __init__(self, path):
+        if isinstance(path, str):
+            abs_path = os.path.abspath(path)
+            self.__parts = tuple(abs_path.split(os.sep))
+            self.__joined = abs_path
+            self.__is_dir = None
+
+        else:
+            self.__parts = path
+            self.__joined = None
+            self.__is_dir = None
+
+    @property
+    def parts(self):
+        return self.__parts
+
+    def join(self, name):
+        return _Path(self.__parts + (name,))
+
+    def relpath(self, base_path):
+        assert self.__parts[: len(base_path.__parts)] == base_path.__parts
+        return "/".join(self.__parts[len(base_path.__parts) :])
+
+    def parents(self):
+        for i in range(len(self.__parts) - 1, 0, -1):
+            yield _Path(self.__parts[:i])
+
+    def isfile(self):
+        if self.__joined is None:
+            self.__joined = "/".join(self.__parts)
+        return os.path.isfile(self.__joined)
+
+    def isdir(self):
+        if self.__is_dir is not None:
+            return self.__is_dir
+        if self.__joined is None:
+            self.__joined = "/".join(self.__parts)
+        self.__is_dir = os.path.isdir(self.__joined)
+        return self.__is_dir
+
+    def __str__(self):
+        if self.__joined is None:
+            self.__joined = "/".join(self.__parts)
+        return self.__joined
+
+
 def _rule_from_pattern(pattern):
     """
     Take a `.gitignore` match pattern, such as "*.py[cod]" or "**/*.bak",
@@ -172,20 +204,21 @@ class _IgnoreRules:
     def __init__(self, rules, base_path):
         self.__rules = rules
         self.__can_return_immediately = not any((r.negation for r in rules))
-        self.__base_path = base_path
+        self.__base_path = _Path(base_path) if isinstance(base_path, str) else base_path
 
     def match(self, path, is_dir=None):
         """
         Because Git allows for nested `.gitignore` files, a `base_path` value
         is required for correct behavior.
         """
-        if is_dir is None:
-            is_dir = os.path.isdir(path)
 
-        rel_path = os.path.relpath(path, self.__base_path)
+        if isinstance(path, str):
+            path = _Path(path)
+
+        if is_dir is None:
+            is_dir = path.isdir()
 
-        if rel_path.startswith(f".{os.sep}"):
-            rel_path = rel_path[2:]
+        rel_path = path.relpath(self.__base_path)
 
         if self.__can_return_immediately:
             return any((r.match(rel_path, is_dir) for r in self.__rules))
@@ -221,13 +254,8 @@ def match(self, rel_path, is_dir):
 
 
 def _seps_non_sep_expr():
-    if os.altsep is None:
-        seps = re.escape(os.sep)
-        non_sep = f"[^{re.escape(os.sep)}]"
-
-    else:
-        seps = f"[{re.escape(os.sep)}{re.escape(os.altsep)}]"
-        non_sep = f"[^{re.escape(os.sep)}{re.escape(os.altsep)}]"
+    seps = re.escape(os.sep)
+    non_sep = f"[^{re.escape(os.sep)}]"
 
     return seps, non_sep
 
diff --git a/tests/test_cache.py b/tests/test_cache.py
index 53a061b..1f7a209 100644
--- a/tests/test_cache.py
+++ b/tests/test_cache.py
@@ -80,9 +80,7 @@ def mock_stat(path):
                 self.assertFalse(matches("/home/vladimir/project/file.txt"))
 
         self.assertEqual(statistics["open"], 2)
-
-        # On Windows and Python 3.7 `os.path.isdir()` does not use `os.stat`. See `Modules/getpath.c`.
-        self.assertIn(statistics["stat"], (6 * (2 + 1) + 5, 6 * (2 + 1)))
+        self.assertEqual(statistics["stat"], 6 + 5)
 
     def test_wrong_symlink(self):
         with tempfile.TemporaryDirectory() as d: