diff --git a/beeb/consts.asm b/beeb/consts.asm
index 3137c91..1daf8f2 100644
--- a/beeb/consts.asm
+++ b/beeb/consts.asm
@@ -71,12 +71,13 @@ PRT_PEN = 16
 
 ; Room related
 ROOM_EMPTY = 70
-BIGGESTROOM = 919 ; Room 22
+BIGGESTROOM = 919 ; In bytes - Room 22
 TITLEROOM = 0
 BEANSTALKROOM = 1
 FIREROOM = 2
 HEARTSROOM = 3
 GAMESTARTROOM = 36
+ENTRANCEHALLROOM = 52
 ALLOTMENTROOM = 58
 
 DIZZY_WIDTH = (3*8)