diff --git a/sys/i386/include/apicreg.h b/sys/i386/include/apicreg.h
index 7b584a075e0..2d6c7ea1cb4 100644
--- a/sys/i386/include/apicreg.h
+++ b/sys/i386/include/apicreg.h
@@ -330,8 +330,13 @@ typedef struct IOAPIC ioapic_t;
 #define APIC_LVTT_DS		0x00001000
 #define APIC_LVTT_M		0x00010000
 #define APIC_LVTT_TM		0x00020000
+# define APIC_LVTT_TM_ONE_SHOT	0x00000000
+# define APIC_LVTT_TM_PERIODIC	0x00020000
 
 
+/* APIC timer current count */
+#define	APIC_TIMER_MAX_COUNT	0xffffffff
+
 /* fields in TDCR */
 #define APIC_TDCR_2		0x00
 #define APIC_TDCR_4		0x01