diff --git a/man2/sched_setscheduler.2 b/man2/sched_setscheduler.2
index 331ebf744..81b449ae0 100644
--- a/man2/sched_setscheduler.2
+++ b/man2/sched_setscheduler.2
@@ -146,6 +146,8 @@ is set appropriately.
 .TP
 .B EINVAL
 The scheduling \fIpolicy\fP is not one of the recognized policies,
+.I pid
+is negative,
 \fIparam\fP is NULL,
 or \fIparam\fP does not make sense for the \fIpolicy\fP.
 .TP