--- freebsd/sys/kern/kern_mib.c	2020-03-29 16:36:17.306435229 +0200
+++ freebsd-new/sys/kern/kern_mib.c	2020-03-29 16:34:29.006535171 +0200
@@ -452,9 +452,9 @@
 MTX_SYSINIT(bootid_lock, &bootid_lk, "bootid generator lock", MTX_DEF);
 
 static int
-sysctl_bootid(SYSCTL_HANDLER_ARGS)
+sysctl_boot_id(SYSCTL_HANDLER_ARGS)
 {
-	static uint8_t boot_id[16];
+	static uint8_t boot_id[8];
 	static bool initialized = false;
 
 	mtx_lock(&bootid_lk);
@@ -471,8 +471,8 @@
 	return (SYSCTL_OUT(req, boot_id, sizeof(boot_id)));
 }
 SYSCTL_PROC(_kern, OID_AUTO, boot_id,
-    CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
-    NULL, 0, sysctl_bootid, "", "Random boot ID");
+    CTLTYPE_U64 | CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
+    NULL, 0, sysctl_boot_id, "LU", "Random boot ID");
 
 /*
  * The osrelease string is copied from the global (osrelease in vers.c) into