diff --git a/py-polars/polars/lazyframe/frame.py b/py-polars/polars/lazyframe/frame.py
index fe997ad59a99..6f60a9d3326e 100644
--- a/py-polars/polars/lazyframe/frame.py
+++ b/py-polars/polars/lazyframe/frame.py
@@ -2475,7 +2475,7 @@ def sink_csv(
         )
 
         return lf.sink_csv(
-            path=path,
+            path=normalize_filepath(path),
             include_bom=include_bom,
             include_header=include_header,
             separator=ord(separator),