diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c
index 62d65fabc721..ac5b73266067 100644
--- a/sys/kern/kern_jail.c
+++ b/sys/kern/kern_jail.c
@@ -241,10 +241,19 @@ jailed(cred)
 /*
  * Return the correct hostname for the passed credential.
  */
-const char *
-getcredhostname(cred)
+void
+getcredhostname(cred, buf, size)
 	struct ucred *cred;
+	char *buf;
+	size_t size;
 {
 
-	return (jailed(cred) ? cred->cr_prison->pr_host : hostname);
+	if (jailed(cred)) {
+		mtx_lock(&cred->cr_prison->pr_mtx);
+		strncpy(buf, cred->cr_prison->pr_host, size);
+		mtx_unlock(&cred->cr_prison->pr_mtx);
+	}
+	else
+		strncpy(buf, hostname, size);
+	buf[size - 1] = '\0';
 }
diff --git a/sys/sys/jail.h b/sys/sys/jail.h
index f9f7b814c133..1fef842a5f7d 100644
--- a/sys/sys/jail.h
+++ b/sys/sys/jail.h
@@ -68,7 +68,7 @@ extern int	jail_sysvipc_allowed;
 struct ucred;
 struct sockaddr;
 int jailed __P((struct ucred *cred));
-const char *getcredhostname __P((struct ucred *cred));
+void getcredhostname __P((struct ucred *cred, char *, size_t));
 int prison_check __P((struct ucred *cred1, struct ucred *cred2));
 void prison_free __P((struct prison *pr));
 u_int32_t prison_getip __P((struct ucred *cred));