diff --git a/lib/libc/sys/kqueue.2 b/lib/libc/sys/kqueue.2
index d0abe5552e9a..73a760e3ddd2 100644
--- a/lib/libc/sys/kqueue.2
+++ b/lib/libc/sys/kqueue.2
@@ -113,6 +113,14 @@ The
 argument
 determines the size of
 .Fa eventlist .
+When
+.Fa nevents
+is zero,
+.Fn kevent
+will return immediately even if there is a
+.Fa timeout
+specified unlike
+.Xr select  2 .
 If
 .Fa timeout
 is a non-NULL pointer, it specifies a maximum interval to wait