diff --git a/sys/arm64/include/bus.h b/sys/arm64/include/bus.h
--- a/sys/arm64/include/bus.h
+++ b/sys/arm64/include/bus.h
@@ -76,6 +76,7 @@
 
 #define	BUS_SPACE_MAXADDR_24BIT	0xFFFFFFUL
 #define	BUS_SPACE_MAXADDR_32BIT 0xFFFFFFFFUL
+#define	BUS_SPACE_MAXADDR_36BIT 0xFFFFFFFFFUL
 #define	BUS_SPACE_MAXADDR_40BIT	0xFFFFFFFFFFUL
 #define	BUS_SPACE_MAXSIZE_24BIT	0xFFFFFFUL
 #define	BUS_SPACE_MAXSIZE_32BIT	0xFFFFFFFFUL