diff --git a/src/smallmap_gui.cpp b/src/smallmap_gui.cpp
--- a/src/smallmap_gui.cpp
+++ b/src/smallmap_gui.cpp
@@ -1151,7 +1151,7 @@ static const WindowDesc _smallmap_desc(
 	WDP_AUTO, WDP_AUTO, 350, 214, 446, 314,
 	WC_SMALLMAP, WC_NONE,
 	WDF_STD_TOOLTIPS | WDF_STD_BTN | WDF_DEF_WIDGET | WDF_STICKY_BUTTON | WDF_RESIZABLE | WDF_UNCLICK_BUTTONS,
-	NULL, _nested_smallmap_widgets, lengthof(_nested_smallmap_widgets)
+	_nested_smallmap_widgets, lengthof(_nested_smallmap_widgets)
 );
 
 void ShowSmallMap()