diff --git a/man3/ctime.3 b/man3/ctime.3
index c5434c84f..d95641444 100644
--- a/man3/ctime.3
+++ b/man3/ctime.3
@@ -44,7 +44,7 @@ localtime_r \- transform date and time to broken-down time or ASCII
 .BI "char *asctime_r(const struct tm *restrict " tm ", char *restrict " buf );
 .PP
 .BI "char *ctime(const time_t *" timep );
-.BI "char *ctime_r(const time_t *" timep ", char *" buf );
+.BI "char *ctime_r(const time_t *restrict " timep ", char *restrict " buf );
 .PP
 .BI "struct tm *gmtime(const time_t *" timep );
 .BI "struct tm *gmtime_r(const time_t *restrict " timep ,
@@ -381,6 +381,12 @@ as obsolete,
 recommending the use of
 .BR strftime (3)
 instead.
+.PP
+POSIX doesn't specify the parameters of
+.BR ctime_r ()
+to be
+.IR restrict ;
+that is specific to glibc.
 .SH NOTES
 The four functions
 .BR asctime (),