diff --git a/stdlib/_csv.pyi b/stdlib/_csv.pyi
index ecea4878907c..efe9ad69bd31 100644
--- a/stdlib/_csv.pyi
+++ b/stdlib/_csv.pyi
@@ -90,6 +90,7 @@ else:
 
 def writer(
     csvfile: SupportsWrite[str],
+    /,
     dialect: _DialectLike = "excel",
     *,
     delimiter: str = ",",
@@ -103,6 +104,7 @@ def writer(
 ) -> _writer: ...
 def reader(
     csvfile: Iterable[str],
+    /,
     dialect: _DialectLike = "excel",
     *,
     delimiter: str = ",",