diff --git a/man3/getlogin.3 b/man3/getlogin.3
index d2e06d768..a4517feed 100644
--- a/man3/getlogin.3
+++ b/man3/getlogin.3
@@ -137,6 +137,20 @@ password database file
 \fI/var/run/utmp\fP
 (traditionally \fI/etc/utmp\fP;
 some libc versions used \fI/var/adm/utmp\fP)
+.SH ATTRIBUTES
+.SS Multithreading(see pthreads(7))
+The
+.BR getlogin ()
+function is not thread-safe.
+.LP
+The
+.BR getlogin_r ()
+function is thread-safe.
+.LP
+The
+.BR cuserid ()
+function is thread-safe with exceptions.
+It is not thread-safe if called with a NULL parameter.
 .SH CONFORMING TO
 .BR getlogin ()
 and