diff --git a/man2/socket.2 b/man2/socket.2
index 5cc07fb48..dfba70ff6 100644
--- a/man2/socket.2
+++ b/man2/socket.2
@@ -53,6 +53,8 @@ socket \- create an endpoint for communication
 .BR socket ()
 creates an endpoint for communication and returns a file descriptor
 that refers to that endpoint.
+The file descriptor returned by a successful call will be
+the lowest-numbered file descriptor not currently open for the process.
 .PP
 The
 .I domain