diff --git a/man2/epoll_wait.2 b/man2/epoll_wait.2
index dddc7aafe..992ea7641 100644
--- a/man2/epoll_wait.2
+++ b/man2/epoll_wait.2
@@ -125,6 +125,13 @@ executing the following calls:
     ready = epoll_wait(epfd, &events, maxevents, timeout);
     sigprocmask(SIG_SETMASK, &origmask, NULL);
 .fi
+.PP
+The
+.I sigmask
+argument may be specified as NULL, in which case
+.BR epoll_pwait ()
+is equivalent to
+.BR epoll_wait ().
 .SH "RETURN VALUE"
 When successful,
 .BR epoll_wait ()