diff --git a/man2/sched_setparam.2 b/man2/sched_setparam.2
index 0ae399636..4d0502c1c 100644
--- a/man2/sched_setparam.2
+++ b/man2/sched_setparam.2
@@ -96,6 +96,13 @@ is set appropriately.
 .SH ERRORS
 .TP
 .B EINVAL
+Invalid arguments:
+.I param
+is NULL or
+.I pid
+is negative
+.TP
+.B EINVAL
 .RB ( sched_setparam ())
 The argument \fIparam\fP does not make sense for the current
 scheduling policy.