diff --git a/src/airport_gui.cpp b/src/airport_gui.cpp
--- a/src/airport_gui.cpp
+++ b/src/airport_gui.cpp
@@ -424,26 +424,26 @@ static const NWidgetPart _nested_build_a
 		NWidget(WWT_CLOSEBOX, COLOUR_DARK_GREEN),
 		NWidget(WWT_CAPTION, COLOUR_DARK_GREEN), SetDataTip(STR_STATION_BUILD_AIRPORT_CAPTION, STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS),
 	EndContainer(),
-	NWidget(WWT_PANEL, COLOUR_DARK_GREEN), SetFill(true, false), SetPIP(2, 0, 2),
-		NWidget(WWT_LABEL, COLOUR_DARK_GREEN), SetDataTip(STR_STATION_BUILD_AIRPORT_CLASS_LABEL, STR_NULL), SetFill(true, false),
-		NWidget(WWT_DROPDOWN, COLOUR_GREY, BAIRW_CLASS_DROPDOWN), SetFill(true, false), SetDataTip(STR_BLACK_STRING, STR_NULL),
+	NWidget(WWT_PANEL, COLOUR_DARK_GREEN), SetFill(1, 0), SetPIP(2, 0, 2),
+		NWidget(WWT_LABEL, COLOUR_DARK_GREEN), SetDataTip(STR_STATION_BUILD_AIRPORT_CLASS_LABEL, STR_NULL), SetFill(1, 0),
+		NWidget(WWT_DROPDOWN, COLOUR_GREY, BAIRW_CLASS_DROPDOWN), SetFill(1, 0), SetDataTip(STR_BLACK_STRING, STR_NULL),
 		NWidget(NWID_HORIZONTAL),
-			NWidget(WWT_MATRIX, COLOUR_GREY, BAIRW_AIRPORT_LIST), SetFill(true, false), SetDataTip(0x501, STR_NULL),
+			NWidget(WWT_MATRIX, COLOUR_GREY, BAIRW_AIRPORT_LIST), SetFill(1, 0), SetDataTip(0x501, STR_NULL),
 			NWidget(WWT_SCROLLBAR, COLOUR_GREY, BAIRW_SCROLLBAR),
 		EndContainer(),
 	EndContainer(),
 	/* Bottom panel. */
 	NWidget(WWT_PANEL, COLOUR_DARK_GREEN, BAIRW_BOTTOMPANEL), SetPIP(2, 2, 2),
-		NWidget(WWT_LABEL, COLOUR_DARK_GREEN), SetDataTip(STR_STATION_BUILD_COVERAGE_AREA_TITLE, STR_NULL), SetFill(true, false),
+		NWidget(WWT_LABEL, COLOUR_DARK_GREEN), SetDataTip(STR_STATION_BUILD_COVERAGE_AREA_TITLE, STR_NULL), SetFill(1, 0),
 		NWidget(NWID_HORIZONTAL),
-			NWidget(NWID_SPACER), SetMinimalSize(14, 0), SetFill(true, false),
+			NWidget(NWID_SPACER), SetMinimalSize(14, 0), SetFill(1, 0),
 			NWidget(NWID_HORIZONTAL, NC_EQUALSIZE),
 				NWidget(WWT_TEXTBTN, COLOUR_GREY, BAIRW_BTN_DONTHILIGHT), SetMinimalSize(60, 12), SetFill(1, 0),
 											SetDataTip(STR_STATION_BUILD_COVERAGE_OFF, STR_STATION_BUILD_COVERAGE_AREA_OFF_TOOLTIP),
 				NWidget(WWT_TEXTBTN, COLOUR_GREY, BAIRW_BTN_DOHILIGHT), SetMinimalSize(60, 12), SetFill(1, 0),
 											SetDataTip(STR_STATION_BUILD_COVERAGE_ON, STR_STATION_BUILD_COVERAGE_AREA_ON_TOOLTIP),
 			EndContainer(),
-			NWidget(NWID_SPACER), SetMinimalSize(14, 0), SetFill(true, false),
+			NWidget(NWID_SPACER), SetMinimalSize(14, 0), SetFill(1, 0),
 		EndContainer(),
 		NWidget(NWID_SPACER), SetMinimalSize(0, 10), SetResize(0, 1), SetFill(1, 0),
 	EndContainer(),