diff --git a/include/time.h b/include/time.h
index 3e1e2b4619e..9252872aba2 100644
--- a/include/time.h
+++ b/include/time.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: time.h,v 1.32 2022/10/25 16:30:30 millert Exp $	*/
+/*	$OpenBSD: time.h,v 1.33 2025/11/20 10:58:11 tb Exp $	*/
 /*	$NetBSD: time.h,v 1.9 1994/10/26 00:56:35 cgd Exp $	*/
 
 /*
@@ -106,7 +106,7 @@ struct tm {
 	int	tm_yday;	/* days since January 1 [0-365] */
 	int	tm_isdst;	/* Daylight Saving Time flag */
 	long	tm_gmtoff;	/* offset from UTC in seconds */
-	char	*tm_zone;	/* timezone abbreviation */
+	const char *tm_zone;	/* timezone abbreviation */
 };
 
 __BEGIN_DECLS
diff --git a/lib/libc/time/ctime.3 b/lib/libc/time/ctime.3
index 0702af3a7f0..44a3a01a22b 100644
--- a/lib/libc/time/ctime.3
+++ b/lib/libc/time/ctime.3
@@ -1,7 +1,7 @@
-.\"	$OpenBSD: ctime.3,v 1.49 2025/06/23 13:53:11 millert Exp $
+.\"	$OpenBSD: ctime.3,v 1.50 2025/11/20 10:58:11 tb Exp $
 .\"
 .\"
-.Dd $Mdocdate: June 23 2025 $
+.Dd $Mdocdate: November 20 2025 $
 .Dt CTIME 3
 .Os
 .Sh NAME
@@ -241,7 +241,7 @@ includes the following fields:
 	int tm_yday;	/* day of year (0 \- 365) */
 	int tm_isdst;	/* is summer time in effect? */
 	long tm_gmtoff;	/* offset from UT in seconds */
-	char *tm_zone;	/* abbreviation of timezone name */
+	const char *tm_zone;	/* abbreviation of timezone name */
 .Ed
 .Pp
 The