diff --git a/src/widgets/dropdown.cpp b/src/widgets/dropdown.cpp
--- a/src/widgets/dropdown.cpp
+++ b/src/widgets/dropdown.cpp
@@ -148,7 +148,7 @@ struct DropdownWindow : Window {
 		this->GetWidget<NWidgetStacked>(DDM_SHOW_SCROLL)->SetDisplayedPlane(scroll ? 0 : SZSP_NONE);
 
 		this->FinishInitNested(&_dropdown_desc, 0);
-		CLRBITS(this->flags4, WF_WHITE_BORDER_MASK);
+		CLRBITS(this->flags, WF_WHITE_BORDER);
 
 		/* Total length of list */
 		int list_height = 0;