diff --git a/tools/Data/include/dstructs.h b/tools/Data/include/dstructs.h
index 13c6d23ef..299b90f94 100644
--- a/tools/Data/include/dstructs.h
+++ b/tools/Data/include/dstructs.h
@@ -24,8 +24,8 @@ enum	PSX_COLLSION_ENUM
 	COLLISION_TYPE_FLAG_STICKY		=COLLISION_TYPE_STICKY << COLLISION_TYPE_FLAG_SHIFT,
 	COLLISION_TYPE_FLAG_WATER		=COLLISION_TYPE_WATER << COLLISION_TYPE_FLAG_SHIFT,
 
-	COLLISION_TYPE_MASK				= 255 << COLLISION_TYPE_FLAG_SHIFT,
-	COLLISION_MASK					= (255-COLLISION_TYPE_MASK)
+	COLLISION_TYPE_MASK				= (0xff << COLLISION_TYPE_FLAG_SHIFT)&0xff,
+	COLLISION_MASK					= (0xff-COLLISION_TYPE_MASK)
 
 };
 enum	PSX_DATA_ENUM