diff --git a/doc/tools/make_rst.py b/doc/tools/make_rst.py
index 703a8144260..6b9ea87cf71 100755
--- a/doc/tools/make_rst.py
+++ b/doc/tools/make_rst.py
@@ -373,7 +373,7 @@ def main():  # type: () -> None
 
     for path in args.path:
         # Cut off trailing slashes so os.path.basename doesn't choke.
-        if path.endswith(os.sep):
+        if path.endswith("/") or path.endswith("\\"):
             path = path[:-1]
 
         if os.path.basename(path) == "modules":