diff --git a/source/level/layercollision.cpp b/source/level/layercollision.cpp
index 84aeaf590..eac702a5b 100644
--- a/source/level/layercollision.cpp
+++ b/source/level/layercollision.cpp
@@ -52,7 +52,7 @@ int			CLayerCollision::getHeightFromGround(int _x,int _y,int _maxHeight)
 	yFraction=16-(_y&0x0f);
 	distanceFromGround=0;
 
-	colHeight=m_collisionTable[(Map[mapX+mapY]*16)+xFraction];
+	colHeight=m_collisionTable[((Map[mapX+mapY]&COLLISION_MASK)*16)+xFraction];
 	if(colHeight)
 	{
 		// Inside a collision block.. find the nearest ground above this point
@@ -66,7 +66,7 @@ int			CLayerCollision::getHeightFromGround(int _x,int _y,int _maxHeight)
 			{
 				return -_maxHeight;
 			}
-			colHeight=m_collisionTable[(Map[mapX+mapY]*16)+xFraction];
+			colHeight=m_collisionTable[((Map[mapX+mapY]&COLLISION_MASK)*16)+xFraction];
 		}
 		distanceFromGround+=yFraction-colHeight;
 		if(distanceFromGround<-_maxHeight)distanceFromGround=-_maxHeight;
@@ -85,7 +85,7 @@ int			CLayerCollision::getHeightFromGround(int _x,int _y,int _maxHeight)
 			{
 				return _maxHeight;
 			}
-			colHeight=m_collisionTable[(Map[mapX+mapY]*16)+xFraction];
+			colHeight=m_collisionTable[((Map[mapX+mapY]&COLLISION_MASK)*16)+xFraction];
 		}
 		distanceFromGround+=yFraction-colHeight;
 		if(distanceFromGround>_maxHeight)distanceFromGround=_maxHeight;
@@ -128,7 +128,7 @@ void CLayerCollision::render(DVECTOR &MapPos)
 			coll=&Map[mapx+(mapy*MapWidth)];
 			for(x=-xoff;x<(33*16)-xoff;x+=16)
 			{
-				switch(*coll)
+				switch((*coll)&COLLISION_MASK)
 				{
 					case 0:
 						break;
diff --git a/source/level/layercollision.h b/source/level/layercollision.h
index b7ff51bfe..d7698a5bd 100644
--- a/source/level/layercollision.h
+++ b/source/level/layercollision.h
@@ -22,7 +22,7 @@ virtual	~CLayerCollision();
 
 virtual	void			shutdown();
 
-		u8				Get(int X,int Y)	{return(Map[X+(Y*MapWidth)]);}
+		u8				Get(int X,int Y)	{return(Map[X+(Y*MapWidth)]&COLLISION_MASK);}
 		int				getHeightFromGround(int _x,int _y,int _maxHeight=32);
 
 #ifdef __SHOW_COLLISION__