diff --git a/include/map.h b/include/map.h
index c5a0a223..0a61c64d 100644
--- a/include/map.h
+++ b/include/map.h
@@ -47,9 +47,9 @@ extern void writemap(natid);
 /* src/lib/subs/border.c */
 extern void border(struct range *, char *, char *);
 
-#define MAP_SHIP	bit(0)
-#define MAP_LAND	bit(1)
-#define MAP_PLANE	bit(2)
+#define MAP_PLANE	bit(0) /* this order must match */
+#define MAP_SHIP	bit(1) /* priority of the map and */
+#define MAP_LAND	bit(2) /* ef_unit_list */
 #define MAP_NUKE	bit(3)
 #define MAP_HIGH	bit(4)
 #define MAP_ALL		MAP_SHIP | MAP_LAND | MAP_PLANE | MAP_NUKE