diff --git a/src/newgrf_object.h b/src/newgrf_object.h
index 4ccca97b8d..2d9fe5665c 100644
--- a/src/newgrf_object.h
+++ b/src/newgrf_object.h
@@ -46,7 +46,7 @@ void ResetObjects();
 /** Class IDs for objects. */
 enum ObjectClassID {
 	OBJECT_CLASS_BEGIN   =    0, ///< The lowest valid value
-	OBJECT_CLASS_MAX     =   32, ///< Maximum number of classes.
+	OBJECT_CLASS_MAX     = 0xFF, ///< Maximum number of classes.
 	INVALID_OBJECT_CLASS = 0xFF, ///< Class for the less fortunate.
 };
 /** Allow incrementing of ObjectClassID variables */