diff --git a/man2/unshare.2 b/man2/unshare.2
index e922e9917..ec9c26e9c 100644
--- a/man2/unshare.2
+++ b/man2/unshare.2
@@ -187,6 +187,13 @@ flag, the caller obtains a full set of capabilities in the new namespace.
 requires that the calling process is not threaded and the user ID and group ID
 of the calling process are mapped user IDs and group IDs in the
 user namespace of the calling process at the time of the call.
+.IP
+.BR CLONE_NEWUSER
+cannot be specified in conjunction with various other
+.BR CLONE_*
+flags.
+For further details, see
+.BR user_namespaces (7).
 .TP
 .BR CLONE_NEWUTS " (since Linux 2.6.19)"
 This flag has the same effect as the