diff --git a/src/genworld_gui.cpp b/src/genworld_gui.cpp
--- a/src/genworld_gui.cpp
+++ b/src/genworld_gui.cpp
@@ -519,7 +519,7 @@ static DropDownList *BuildMapsizeDropDow
 {
 	DropDownList *list = new DropDownList();
 
-	for (uint i = 6; i <= 11; i++) {
+	for (uint i = MIN_MAP_SIZE_BITS; i <= MAX_MAP_SIZE_BITS; i++) {
 		DropDownListParamStringItem *item = new DropDownListParamStringItem(STR_JUST_INT, i, false);
 		item->SetParam(0, 1 << i);
 		list->push_back(item);