diff --git a/src/emu/memory.h b/src/emu/memory.h
index 7cde733db3b..10b947f90f6 100644
--- a/src/emu/memory.h
+++ b/src/emu/memory.h
@@ -687,7 +687,7 @@ address_map *construct_map_##_name(address_map *map)					\
 
 #define AM_SIZE_MEMBER(_struct, _member)								\
 	if (Machine != NULL && Machine->driver_data != NULL)				\
-		map->size = &((_struct *)Machine->driver_data)->(_member);		\
+		map->size = &((_struct *)Machine->driver_data)->_member;		\
 
 /* ----- common shortcuts ----- */
 #define AM_READWRITE(_read,_write)			AM_READ(_read) AM_WRITE(_write)