Index: sys/kern/kern_mib.c
===================================================================
--- sys/kern/kern_mib.c
+++ sys/kern/kern_mib.c
@@ -316,9 +316,9 @@
 }
 
 SYSCTL_PROC(_kern, KERN_HOSTNAME, hostname,
-    CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
-    (void *)(offsetof(struct prison, pr_hostname)), MAXHOSTNAMELEN,
-    sysctl_hostname, "A", "Hostname");
+    CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE |
+    CTLFLAG_CAPRD, (void *)(offsetof(struct prison, pr_hostname)),
+    MAXHOSTNAMELEN, sysctl_hostname, "A", "Hostname");
 SYSCTL_PROC(_kern, KERN_NISDOMAINNAME, domainname,
     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
     (void *)(offsetof(struct prison, pr_domainname)), MAXHOSTNAMELEN,