diff --git a/ext/socket/udpsocket.c b/ext/socket/udpsocket.c
index 86d18f4fae..c4fdd5a857 100644
--- a/ext/socket/udpsocket.c
+++ b/ext/socket/udpsocket.c
@@ -194,7 +194,7 @@ udp_send(int argc, VALUE *argv, VALUE sock)
 
 /*
  * call-seq:
- *   udpsocket.recvfrom_nonblock(maxlen [, flags [, options]) => [mesg, sender_inet_addr]
+ *   udpsocket.recvfrom_nonblock(maxlen [, flags [, options]]) => [mesg, sender_inet_addr]
  *
  * Receives up to _maxlen_ bytes from +udpsocket+ using recvfrom(2) after
  * O_NONBLOCK is set for the underlying file descriptor.
diff --git a/ext/socket/unixsocket.c b/ext/socket/unixsocket.c
index 9003529042..f768fbc126 100644
--- a/ext/socket/unixsocket.c
+++ b/ext/socket/unixsocket.c
@@ -131,7 +131,7 @@ unix_path(VALUE sock)
 
 /*
  * call-seq:
- *   unixsocket.recvfrom(maxlen [, flags[, outbuf]) => [mesg, unixaddress]
+ *   unixsocket.recvfrom(maxlen [, flags[, outbuf]]) => [mesg, unixaddress]
  *
  * Receives a message via _unixsocket_.
  *