diff --git a/source/room.cpp b/source/room.cpp
index c6a76e5..dffb265 100644
--- a/source/room.cpp
+++ b/source/room.cpp
@@ -123,7 +123,7 @@ namespace room
     //void load(int x, int y, int8_t xp, int8_t xn, int8_t yp, int8_t yn, uint8_t col, uint8_t floor, uint8_t walls, uint8_t door, uint8_t walldoor)
     void load(int room, const int door)
     {
-        if (room > 64 || room < 0) {
+        if (room > MAX_ROOMS || room < 0) {
             room = find_next_room();
             exits[inverse_door(door)] = room;
             if (door<4 && door_height[door]==-1) door_height[door]=0;
diff --git a/source/room.h b/source/room.h
index c7c8000..c247a50 100644
--- a/source/room.h
+++ b/source/room.h
@@ -2,6 +2,8 @@
 #include "misc.h"
 #include <vector>
 
+#define MAX_ROOMS 64
+
 #define NO_DOOR 0
 #define DOOR_XP 1
 #define DOOR_XN 2