diff --git a/tw2/core/resources.py b/tw2/core/resources.py
index 23d4c33..775f2d7 100644
--- a/tw2/core/resources.py
+++ b/tw2/core/resources.py
@@ -360,7 +360,7 @@ def __call__(self, environ, start_response):
                 if '..' in path:  # protect against directory traversal
                     raise IOError()
                 for d in self._dirs:
-                    if path.startswith(d):
+                    if path.startswith(d.replace('\\', '/')):
                         break
                 else:
                     raise IOError()