diff --git a/CHANGELOG.md b/CHANGELOG.md
index 87c1d05..980f96e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,9 @@ ambiguous situations.
 
 ## Unreleased
 
+### Changed
+- Use `/` instead of `\` as path separator for (regex) rules on Windows
+
 ## 3.0.1 - 2021-06-01
 
 ### Added
diff --git a/PFERD/transformer.py b/PFERD/transformer.py
index 83ffde4..ed123eb 100644
--- a/PFERD/transformer.py
+++ b/PFERD/transformer.py
@@ -10,7 +10,7 @@ from pathlib import PurePath
 from typing import Dict, Optional, Sequence, Union
 
 from .logging import log
-from .utils import fmt_path
+from .utils import fmt_path, str_path
 
 
 class Rule(ABC):
@@ -116,7 +116,7 @@ class ReRule(Rule):
         self._right = right
 
     def transform(self, path: PurePath) -> Union[PurePath, bool]:
-        if match := re.fullmatch(self._left, str(path)):
+        if match := re.fullmatch(self._left, str_path(path)):
             if isinstance(self._right, bool):
                 return self._right or path
 
diff --git a/PFERD/utils.py b/PFERD/utils.py
index 397feda..7c7b6f4 100644
--- a/PFERD/utils.py
+++ b/PFERD/utils.py
@@ -91,8 +91,14 @@ def url_set_query_params(url: str, params: Dict[str, str]) -> str:
     return result
 
 
+def str_path(path: PurePath) -> str:
+    if not path.parts:
+        return "."
+    return "/".join(path.parts)
+
+
 def fmt_path(path: PurePath) -> str:
-    return repr(str(path))
+    return repr(str_path(path))
 
 
 def fmt_real_path(path: Path) -> str: