diff --git a/Modules/_interpchannelsmodule.c b/Modules/_interpchannelsmodule.c
index ff8dacf5bd1ad0..47dbdeb9a37c44 100644
--- a/Modules/_interpchannelsmodule.c
+++ b/Modules/_interpchannelsmodule.c
@@ -2977,7 +2977,7 @@ channelsmod_send(PyObject *self, PyObject *args, PyObject *kwds)
 }
 
 PyDoc_STRVAR(channelsmod_send_doc,
-"channel_send(cid, obj, blocking=True)\n\
+"channel_send(cid, obj, *, blocking=True, timeout=None)\n\
 \n\
 Add the object's data to the channel's queue.\n\
 By default this waits for the object to be received.");
@@ -3027,7 +3027,7 @@ channelsmod_send_buffer(PyObject *self, PyObject *args, PyObject *kwds)
 }
 
 PyDoc_STRVAR(channelsmod_send_buffer_doc,
-"channel_send_buffer(cid, obj, blocking=True)\n\
+"channel_send_buffer(cid, obj, *, blocking=True, timeout=None)\n\
 \n\
 Add the object's buffer to the channel's queue.\n\
 By default this waits for the object to be received.");