diff --git a/man3/mbrtowc.3 b/man3/mbrtowc.3
index 129554e85..6e9bb5bda 100644
--- a/man3/mbrtowc.3
+++ b/man3/mbrtowc.3
@@ -171,6 +171,12 @@ if it couldn't parse a complete multibyte
 character, meaning that
 .I n
 should be increased.
+.SH ATTRIBUTES
+.SS Multithreading (see pthreads(7))
+The
+.BR mbrtowc ()
+function is thread-safe with exceptions.
+It is not thread-safe if called with a NULL \fIps\fP parameter.
 .SH CONFORMING TO
 C99.
 .SH NOTES