--- Libc/Libc-825.26/sys/nanosleep.2
+++ Libc/Libc-583/sys/nanosleep.2
@@ -87,6 +87,13 @@
 .Fn nanosleep
 call fails if:
 .Bl -tag -width Er
+.It Bq Er EFAULT
+Either
+.Fa rqtp
+or
+.Fa rmtp
+points to memory that is not a valid part of the process
+address space.
 .It Bq Er EINTR
 .Fn nanosleep
 was interrupted by the delivery of a signal.
@@ -94,6 +101,9 @@
 .Fa rqtp
 specified a nanosecond value less than zero
 or greater than or equal to 1000 million.
+.It Bq Er ENOSYS
+.Fn nanosleep
+is not supported by this implementation.
 .El
 .Sh SEE ALSO
 .Xr sigsuspend 2 ,