diff --git a/sys/x86/x86/cpu_machdep.c b/sys/x86/x86/cpu_machdep.c
index 2bdef5165cf..0a516445b77 100644
--- a/sys/x86/x86/cpu_machdep.c
+++ b/sys/x86/x86/cpu_machdep.c
@@ -723,7 +723,7 @@ SYSINIT(cpu_idle_tun, SI_SUB_CPU, SI_ORDER_MIDDLE, cpu_idle_tun, NULL);
 static int panic_on_nmi = 1;
 SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RWTUN,
     &panic_on_nmi, 0,
-    "Panic on NMI");
+    "Panic on NMI raised by hardware failure");
 int nmi_is_broadcast = 1;
 SYSCTL_INT(_machdep, OID_AUTO, nmi_is_broadcast, CTLFLAG_RWTUN,
     &nmi_is_broadcast, 0,
@@ -732,7 +732,7 @@ SYSCTL_INT(_machdep, OID_AUTO, nmi_is_broadcast, CTLFLAG_RWTUN,
 int kdb_on_nmi = 1;
 SYSCTL_INT(_machdep, OID_AUTO, kdb_on_nmi, CTLFLAG_RWTUN,
     &kdb_on_nmi, 0,
-    "Go to KDB on NMI");
+    "Go to KDB on NMI with unknown source");
 #endif
 
 #ifdef DEV_ISA