diff --git a/stand/kboot/host_syscall.h b/stand/kboot/host_syscall.h
--- a/stand/kboot/host_syscall.h
+++ b/stand/kboot/host_syscall.h
@@ -123,6 +123,8 @@
 #define HOST_MAP_FIXED		0x10
 #define HOST_MAP_ANONYMOUS	0x20
 
+#define HOST_MAP_FAILED		((void *)-1)
+
 /* Mount flags from uapi */
 #define MS_RELATIME (1 << 21)