diff --git a/man3/mq_open.3 b/man3/mq_open.3
index e4d36e8fc..e2c6fde28 100644
--- a/man3/mq_open.3
+++ b/man3/mq_open.3
@@ -70,6 +70,13 @@ Zero or more of the following flags can additionally be
 in
 .IR oflag :
 .TP
+.BR O_CLOEXEC " (since Linux 2.6.26)"
+.\" commit 269f21344b23e552c21c9e2d7ca258479dcd7a0a
+Set the close-on-exec flag for the message queue descriptor.
+See
+.BR open (2)
+for a discussion of why this flag is useful.
+.TP
 .B O_CREAT
 Create the message queue if it does not exist.
 The owner (user ID) of the message queue is set to the effective