diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 31d9e0e..4b938ff 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -2075,7 +2075,7 @@ reverse flag can be set to request the result in descending order.
 [end disabled clinic input]*/
 
 PyDoc_STRVAR(builtin_sorted__doc__,
-"sorted($module, iterable, key=None, reverse=False)\n"
+"sorted($module, iterable, /, key=None, reverse=False)\n"
 "--\n"
 "\n"
 "Return a new list containing all items from the iterable in ascending order.\n"