diff --git a/src/input.c b/src/input.c
index d10e2f9232..c2d63a34c4 100644
--- a/src/input.c
+++ b/src/input.c
@@ -1123,13 +1123,17 @@ void input_state_widget_pressed(int x, int y, int state, int widgetIndex, rct_wi
 
 				if (w->classification == WC_DROPDOWN) {
 					dropdown_index = dropdown_index_from_point(x, y, w);
-					if (dropdown_index == -1)goto dropdown_cleanup;
+					if (dropdown_index == -1) {
+						goto dropdown_cleanup;
+					}
 
-					// _dropdown_unknown?? highlighted?
-					if (dropdown_index < 64 && gDropdownItemsDisabled & (1ULL << dropdown_index))goto dropdown_cleanup;
+					if (dropdown_index < 64 && gDropdownItemsDisabled & (1ULL << dropdown_index)) {
+						goto dropdown_cleanup;
+					}
 
-					// gDropdownItemsFormat[dropdown_index] will not work until all windows that use dropdown decompiled
-					if (RCT2_ADDRESS(0x9DEBA4, uint16)[dropdown_index] == 0)goto dropdown_cleanup;
+					if (gDropdownItemsFormat[dropdown_index] == 0) {
+						goto dropdown_cleanup;
+					}
 				}
 				else {
 					if (cursor_w_class != w->classification || cursor_w_number != w->number || widgetIndex != cursor_widgetIndex)
@@ -1209,14 +1213,15 @@ void input_state_widget_pressed(int x, int y, int state, int widgetIndex, rct_wi
 			window_tooltip_show(STR_COLOUR_NAMES_START + dropdown_index, x, y);
 		}
 
-		// _dropdown_unknown?? highlighted?
-		if (dropdown_index < 64 && gDropdownItemsDisabled & (1ULL << dropdown_index))return;
+		if (dropdown_index < 64 && gDropdownItemsDisabled & (1ULL << dropdown_index)) {
+			return;
+		}
 
-		// gDropdownItemsFormat[dropdown_index] will not work until all windows that use dropdown decompiled
-		if (RCT2_ADDRESS(0x9DEBA4, uint16)[dropdown_index] == 0)return;
+		if (gDropdownItemsFormat[dropdown_index] == 0) {
+			return;
+		}
 
-		// _dropdown_highlighted_index
-		RCT2_GLOBAL(0x009DEBA2, sint16) = dropdown_index;
+		gDropdownHighlightedIndex = dropdown_index;
 		window_invalidate_by_class(WC_DROPDOWN);
 	} else {
 		gDropdownLastColourHover = -1;
diff --git a/src/windows/banner.c b/src/windows/banner.c
index a8bba69e64..6ff97c3bb4 100644
--- a/src/windows/banner.c
+++ b/src/windows/banner.c
@@ -239,7 +239,7 @@ static void window_banner_mousedown(int widgetIndex, rct_window*w, rct_widget* w
 			13, 
 			widget->right - widget->left - 3);
 		
-		gDropdownItemsChecked = 1 << (banner->text_colour - 1);
+		dropdown_set_checked(banner->text_colour - 1, true);
 		break;
 	}
 }
diff --git a/src/windows/dropdown.c b/src/windows/dropdown.c
index cce9070f9f..a593e4c69f 100644
--- a/src/windows/dropdown.c
+++ b/src/windows/dropdown.c
@@ -47,16 +47,38 @@ int _dropdown_num_columns;
 int _dropdown_num_rows;
 int _dropdown_item_width;
 int _dropdown_item_height;
-int _dropdown_highlighted_index;
 
 int gDropdownNumItems;
 uint16 gDropdownItemsFormat[64];
 sint64 gDropdownItemsArgs[64];
-// Replaces 0x009DED38
 uint64 gDropdownItemsChecked;
 uint64 gDropdownItemsDisabled;
 bool gDropdownIsColour;
 int gDropdownLastColourHover;
+int gDropdownHighlightedIndex;
+
+bool dropdown_is_checked(int index)
+{
+	return gDropdownItemsChecked & (1ULL << index);
+}
+
+void dropdown_set_checked(int index, bool value)
+{
+	if (value) {
+		gDropdownItemsChecked |= 1ULL << index;
+	} else {
+		gDropdownItemsChecked &= ~(1ULL << index);
+	}
+}
+
+void dropdown_set_disabled(int index, bool value)
+{
+	if (value) {
+		gDropdownItemsDisabled |= 1ULL << index;
+	} else {
+		gDropdownItemsDisabled &= ~(1ULL << index);
+	}
+}
 
 static void window_dropdown_paint(rct_window *w, rct_drawpixelinfo *dpi);
 
@@ -178,19 +200,11 @@ void window_dropdown_show_text_custom_width(int x, int y, int extray, uint8 colo
 	w->colours[0] = colour;
 
 	// Input state
-	_dropdown_highlighted_index = -1;
+	gDropdownHighlightedIndex = -1;
 	gDropdownItemsDisabled = 0;
 	gDropdownItemsChecked = 0;
-	RCT2_GLOBAL(RCT2_ADDRESS_INPUT_STATE, sint8) = INPUT_STATE_DROPDOWN_ACTIVE;
-
-	// Copy the following properties until all use of it is decompiled
-	RCT2_GLOBAL(0x009DEBA0, sint16) = gDropdownNumItems;
-	RCT2_GLOBAL(0x009DED44, sint32) = _dropdown_num_columns;
-	RCT2_GLOBAL(0x009DED48, sint32) = _dropdown_num_rows;
-	RCT2_GLOBAL(0x009DED40, sint32) = _dropdown_item_width;
-	RCT2_GLOBAL(0x009DED3C, sint32) = _dropdown_item_height;
-	RCT2_GLOBAL(0x009DEBA2, sint16) = _dropdown_highlighted_index;
 	gDropdownIsColour = false;
+	RCT2_GLOBAL(RCT2_ADDRESS_INPUT_STATE, sint8) = INPUT_STATE_DROPDOWN_ACTIVE;
 }
 
 /**
@@ -257,18 +271,13 @@ void window_dropdown_show_image(int x, int y, int extray, uint8 colour, uint8 fl
 	w->colours[0] = colour;
 
 	// Input state
-	_dropdown_highlighted_index = -1;
+	gDropdownHighlightedIndex = -1;
 	gDropdownItemsDisabled = 0;
 	gDropdownItemsChecked = 0;
 	RCT2_GLOBAL(RCT2_ADDRESS_INPUT_STATE, sint8) = INPUT_STATE_DROPDOWN_ACTIVE;
 
 	// Copy the following properties until all use of it is decompiled
-	RCT2_GLOBAL(0x009DEBA0, sint16) = gDropdownNumItems;
-	RCT2_GLOBAL(0x009DED44, sint32) = _dropdown_num_columns;
-	RCT2_GLOBAL(0x009DED48, sint32) = _dropdown_num_rows;
-	RCT2_GLOBAL(0x009DED40, sint32) = _dropdown_item_width;
-	RCT2_GLOBAL(0x009DED3C, sint32) = _dropdown_item_height;
-	RCT2_GLOBAL(0x009DEBA2, sint16) = _dropdown_highlighted_index;
+	gDropdownHighlightedIndex = gDropdownHighlightedIndex;
 	gDropdownIsColour = false;
 }
 
@@ -283,7 +292,7 @@ static void window_dropdown_paint(rct_window *w, rct_drawpixelinfo *dpi)
 
 	window_draw_widgets(w, dpi);
 
-	_dropdown_highlighted_index = RCT2_GLOBAL(0x009DEBA2, sint16);
+	gDropdownHighlightedIndex = gDropdownHighlightedIndex;
 	for (int i = 0; i < gDropdownNumItems; i++) {
 		cell_x = i % _dropdown_num_columns;
 		cell_y = i / _dropdown_num_columns;
@@ -306,7 +315,7 @@ static void window_dropdown_paint(rct_window *w, rct_drawpixelinfo *dpi)
 			}
 		} else {
 			// 
-			if (i == _dropdown_highlighted_index) {
+			if (i == gDropdownHighlightedIndex) {
 				l = w->x + 2 + (cell_x * _dropdown_item_width);
 				t = w->y + 2 + (cell_y * _dropdown_item_height);
 				r = l + _dropdown_item_width - 1;
@@ -318,7 +327,7 @@ static void window_dropdown_paint(rct_window *w, rct_drawpixelinfo *dpi)
 			if (item == (uint16)-1 || item == (uint16)-2) {
 				// Image item
 				image = *((uint32*)&gDropdownItemsArgs[i]);
-				if (item == (uint16)-2 && _dropdown_highlighted_index == i)
+				if (item == (uint16)-2 && gDropdownHighlightedIndex == i)
 					image++;
 
 				gfx_draw_sprite(
@@ -329,13 +338,15 @@ static void window_dropdown_paint(rct_window *w, rct_drawpixelinfo *dpi)
 				);
 			} else {
 				// Text item
-				if (i < 64)
-					if (gDropdownItemsChecked & (1ULL << i))
+				if (i < 64) {
+					if (dropdown_is_checked(i)) {
 						item++;
+					}
+				}
 
 				// Calculate colour
 				colour = w->colours[0] & 0x7F;
-				if (i == _dropdown_highlighted_index)
+				if (i == gDropdownHighlightedIndex)
 					colour = 2;
 				if (gDropdownItemsDisabled & (1ULL << i))
 					if (i < 64)
@@ -358,7 +369,8 @@ static void window_dropdown_paint(rct_window *w, rct_drawpixelinfo *dpi)
 /* New function based on 6e914e 
  * returns -1 if index is invalid
  */
-int dropdown_index_from_point(int x, int y, rct_window* w){
+int dropdown_index_from_point(int x, int y, rct_window *w)
+{
 	int top = y - w->y - 2;
 	if (top < 0) return -1;
 
@@ -367,20 +379,14 @@ int dropdown_index_from_point(int x, int y, rct_window* w){
 	left -= 2;
 	if (left < 0) return -1;
 
-	// _dropdown_item_width
-	int column_no = left / RCT2_GLOBAL(0x009DED40, sint32);
-	// _dropdown_no_columns
-	if (column_no >= RCT2_GLOBAL(0x009DED44, sint32)) return -1;	
-	
-	// _dropdown_item_height
-	int row_no = top / RCT2_GLOBAL(0x9DED3C, uint8);
-	// _dropdown_no_rows
-	if (row_no >= RCT2_GLOBAL(0x009DED48, sint32)) return -1;
+	int column_no = left / _dropdown_item_width;
+	if (column_no >= _dropdown_num_columns) return -1;
 
-	// _dropdown_no_columns
-	int dropdown_index = row_no * RCT2_GLOBAL(0x009DED44, sint32) + column_no;
-	// _dropdown_no_items
-	if (dropdown_index >= RCT2_GLOBAL(0x009DEBA0, sint16)) return -1;
+	int row_no = top / _dropdown_item_height;
+	if (row_no >= _dropdown_num_rows) return -1;
+
+	int dropdown_index = row_no * _dropdown_num_columns + column_no;
+	if (dropdown_index >= gDropdownNumItems) return -1;
 
 	return dropdown_index;
 }
@@ -413,7 +419,7 @@ void window_dropdown_show_colour_available(rct_window *w, rct_widget *widget, ui
 	for (i = 0; i < 32; i++) {
 		if (availableColours & (1 << i)) {
 			if (selectedColour == i)
-				RCT2_GLOBAL(0x009DEBA2, sint16) = i;
+				gDropdownHighlightedIndex = i;
 
 			gDropdownItemsFormat[i] = 0xFFFE;
 			gDropdownItemsArgs[i] = ((uint64)i << 32) | (0x20000000 | (i << 19) | 5059);
diff --git a/src/windows/dropdown.h b/src/windows/dropdown.h
index fbaee52ee4..5096e2ae92 100644
--- a/src/windows/dropdown.h
+++ b/src/windows/dropdown.h
@@ -39,6 +39,10 @@ extern uint64 gDropdownItemsChecked;
 extern uint64 gDropdownItemsDisabled;
 extern bool gDropdownIsColour;
 extern int gDropdownLastColourHover;
+extern int gDropdownHighlightedIndex;
+
+void dropdown_set_checked(int index, bool value);
+void dropdown_set_disabled(int index, bool value);
 
 void window_dropdown_show_text(int x, int y, int extray, uint8 colour, uint8 flags, int num_items);
 void window_dropdown_show_text_custom_width(int x, int y, int extray, uint8 colour, uint8 flags, int num_items, int width);
diff --git a/src/windows/editor_objective_options.c b/src/windows/editor_objective_options.c
index fd67695778..1712de45fd 100644
--- a/src/windows/editor_objective_options.c
+++ b/src/windows/editor_objective_options.c
@@ -496,7 +496,7 @@ static void window_editor_objective_options_show_objective_dropdown(rct_window *
 	objectiveType = RCT2_GLOBAL(RCT2_ADDRESS_OBJECTIVE_TYPE, uint8);
 	for (i = 0; i < numItems; i++) {
 		if (gDropdownItemsArgs[i] - STR_OBJECTIVE_DROPDOWN_NONE == objectiveType) {
-			gDropdownItemsChecked = (1 << i);
+			dropdown_set_checked(i, true);
 			break;
 		}
 	}
@@ -522,7 +522,7 @@ static void window_editor_objective_options_show_climate_dropdown(rct_window *w)
 		4,
 		dropdownWidget->right - dropdownWidget->left - 3
 	);
-	gDropdownItemsChecked = (1 << RCT2_GLOBAL(RCT2_ADDRESS_CLIMATE, uint8));
+	dropdown_set_checked(RCT2_GLOBAL(RCT2_ADDRESS_CLIMATE, uint8), true);
 }
 
 static void window_editor_objective_options_show_category_dropdown(rct_window *w)
@@ -546,7 +546,7 @@ static void window_editor_objective_options_show_category_dropdown(rct_window *w
 		5,
 		dropdownWidget->right - dropdownWidget->left - 3
 	);
-	gDropdownItemsChecked = (1 << s6Info->category);
+	dropdown_set_checked(s6Info->category, true);
 }
 
 static void window_editor_objective_options_arg_1_increase(rct_window *w)
diff --git a/src/windows/editor_scenario_options.c b/src/windows/editor_scenario_options.c
index bb6c71fa4f..24ee1454e4 100644
--- a/src/windows/editor_scenario_options.c
+++ b/src/windows/editor_scenario_options.c
@@ -1035,7 +1035,7 @@ static void window_editor_scenario_options_park_mousedown(int widgetIndex, rct_w
 			dropdownWidget->right - dropdownWidget->left - 3
 		);
 
-		gDropdownItemsChecked = 1 << (RCT2_GLOBAL(RCT2_ADDRESS_PARK_FLAGS, uint32) & PARK_FLAGS_PARK_FREE_ENTRY ? 0 : 1);
+		dropdown_set_checked((RCT2_GLOBAL(RCT2_ADDRESS_PARK_FLAGS, uint32) & PARK_FLAGS_PARK_FREE_ENTRY ? 0 : 1), true);
 		break;
 	}
 }
diff --git a/src/windows/finances.c b/src/windows/finances.c
index b61e436346..11ad495297 100644
--- a/src/windows/finances.c
+++ b/src/windows/finances.c
@@ -1298,7 +1298,7 @@ static void window_finances_research_mousedown(int widgetIndex, rct_window *w, r
 	);
 
 	int currentResearchLevel = RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_RESEARCH_LEVEL, uint8);
-	gDropdownItemsChecked = (1 << currentResearchLevel);
+	dropdown_set_checked(currentResearchLevel, true);
 }
 
 /**
diff --git a/src/windows/guest_list.c b/src/windows/guest_list.c
index 3f3bd0cd2f..d1b097b92b 100644
--- a/src/windows/guest_list.c
+++ b/src/windows/guest_list.c
@@ -352,7 +352,7 @@ static void window_guest_list_mousedown(int widgetIndex, rct_window*w, rct_widge
 			gDropdownItemsFormat[i] = 1142;
 			gDropdownItemsArgs[i] = STR_PAGE_1 + i;
 		}
-		gDropdownItemsChecked = (1 << _window_guest_list_selected_view);
+		dropdown_set_checked(_window_guest_list_selected_view, true);
 		break;
 	case WIDX_INFO_TYPE_DROPDOWN_BUTTON:
 		widget = &w->widgets[widgetIndex - 1];
@@ -372,7 +372,7 @@ static void window_guest_list_mousedown(int widgetIndex, rct_window*w, rct_widge
 			widget->right - widget->left - 3
 		);
 
-		gDropdownItemsChecked = (1 << _window_guest_list_selected_view);
+		dropdown_set_checked(_window_guest_list_selected_view, true);
 		break;
 	}
 }
diff --git a/src/windows/land.c b/src/windows/land.c
index 94f9e4200b..82cb1e99cd 100644
--- a/src/windows/land.c
+++ b/src/windows/land.c
@@ -222,7 +222,7 @@ static void window_land_mousedown(int widgetIndex, rct_window*w, rct_widget* wid
 			gDropdownItemsFormat[i] = -1;
 			gDropdownItemsArgs[i] = SPR_FLOOR_TEXTURE_GRASS + window_land_floor_texture_order[i];
 			if (window_land_floor_texture_order[i] == _selectedFloorTexture)
-				RCT2_GLOBAL(0x009DEBA2, sint16) = i;
+				gDropdownHighlightedIndex = i;
 		}
 		window_dropdown_show_image(
 			w->x + widget->left, w->y + widget->top,
@@ -239,7 +239,7 @@ static void window_land_mousedown(int widgetIndex, rct_window*w, rct_widget* wid
 			gDropdownItemsFormat[i] = -1;
 			gDropdownItemsArgs[i] = SPR_WALL_TEXTURE_ROCK + window_land_wall_texture_order[i];
 			if (window_land_wall_texture_order[i] == _selectedWallTexture)
-				RCT2_GLOBAL(0x009DEBA2, sint16) = i;
+				gDropdownHighlightedIndex = i;
 		}
 		window_dropdown_show_image(
 			w->x + widget->left, w->y + widget->top,
@@ -268,7 +268,7 @@ static void window_land_dropdown(rct_window *w, int widgetIndex, int dropdownInd
 	switch (widgetIndex) {
 	case WIDX_FLOOR:
 		if (dropdownIndex == -1)
-			dropdownIndex = RCT2_GLOBAL(0x009DEBA2, sint16);
+			dropdownIndex = gDropdownHighlightedIndex;
 
 		type = (dropdownIndex == -1) ?
 			_selectedFloorTexture :
@@ -284,7 +284,7 @@ static void window_land_dropdown(rct_window *w, int widgetIndex, int dropdownInd
 		break;
 	case WIDX_WALL:
 		if (dropdownIndex == -1)
-			dropdownIndex = RCT2_GLOBAL(0x009DEBA2, sint16);
+			dropdownIndex = gDropdownHighlightedIndex;
 
 		type = (dropdownIndex == -1) ?
 			_selectedWallTexture :
diff --git a/src/windows/mapgen.c b/src/windows/mapgen.c
index e641556f2c..87d9fe573e 100644
--- a/src/windows/mapgen.c
+++ b/src/windows/mapgen.c
@@ -536,7 +536,7 @@ static void window_mapgen_base_mousedown(int widgetIndex, rct_window *w, rct_wid
 			gDropdownItemsFormat[i] = -1;
 			gDropdownItemsArgs[i] = SPR_FLOOR_TEXTURE_GRASS + window_land_floor_texture_order[i];
 			if (window_land_floor_texture_order[i] == _floorTexture)
-				RCT2_GLOBAL(0x009DEBA2, sint16) = i;
+				gDropdownHighlightedIndex = i;
 		}
 		window_dropdown_show_image(
 			w->x + widget->left, w->y + widget->top,
@@ -553,7 +553,7 @@ static void window_mapgen_base_mousedown(int widgetIndex, rct_window *w, rct_wid
 			gDropdownItemsFormat[i] = -1;
 			gDropdownItemsArgs[i] = SPR_WALL_TEXTURE_ROCK + window_land_wall_texture_order[i];
 			if (window_land_wall_texture_order[i] == _wallTexture)
-				RCT2_GLOBAL(0x009DEBA2, sint16) = i;
+				gDropdownHighlightedIndex = i;
 		}
 		window_dropdown_show_image(
 			w->x + widget->left, w->y + widget->top,
@@ -575,7 +575,7 @@ static void window_mapgen_base_dropdown(rct_window *w, int widgetIndex, int drop
 	switch (widgetIndex) {
 	case WIDX_FLOOR_TEXTURE:
 		if (dropdownIndex == -1)
-			dropdownIndex = RCT2_GLOBAL(0x009DEBA2, sint16);
+			dropdownIndex = gDropdownHighlightedIndex;
 
 		type = (dropdownIndex == -1) ?
 			_floorTexture :
@@ -591,7 +591,7 @@ static void window_mapgen_base_dropdown(rct_window *w, int widgetIndex, int drop
 		break;
 	case WIDX_WALL_TEXTURE:
 		if (dropdownIndex == -1)
-			dropdownIndex = RCT2_GLOBAL(0x009DEBA2, sint16);
+			dropdownIndex = gDropdownHighlightedIndex;
 
 		type = (dropdownIndex == -1) ?
 			_wallTexture :
@@ -859,7 +859,7 @@ static void window_mapgen_simplex_mousedown(int widgetIndex, rct_window *w, rct_
 			gDropdownItemsFormat[i] = -1;
 			gDropdownItemsArgs[i] = SPR_FLOOR_TEXTURE_GRASS + window_land_floor_texture_order[i];
 			if (window_land_floor_texture_order[i] == _floorTexture)
-				RCT2_GLOBAL(0x009DEBA2, sint16) = i;
+				gDropdownHighlightedIndex = i;
 		}
 		window_dropdown_show_image(
 			w->x + widget->left, w->y + widget->top,
@@ -876,7 +876,7 @@ static void window_mapgen_simplex_mousedown(int widgetIndex, rct_window *w, rct_
 			gDropdownItemsFormat[i] = -1;
 			gDropdownItemsArgs[i] = SPR_WALL_TEXTURE_ROCK + window_land_wall_texture_order[i];
 			if (window_land_wall_texture_order[i] == _wallTexture)
-				RCT2_GLOBAL(0x009DEBA2, sint16) = i;
+				gDropdownHighlightedIndex = i;
 		}
 		window_dropdown_show_image(
 			w->x + widget->left, w->y + widget->top,
@@ -898,7 +898,7 @@ static void window_mapgen_simplex_dropdown(rct_window *w, int widgetIndex, int d
 	switch (widgetIndex) {
 	case WIDX_SIMPLEX_FLOOR_TEXTURE:
 		if (dropdownIndex == -1)
-			dropdownIndex = RCT2_GLOBAL(0x009DEBA2, sint16);
+			dropdownIndex = gDropdownHighlightedIndex;
 
 		type = (dropdownIndex == -1) ?
 		_floorTexture :
@@ -915,7 +915,7 @@ static void window_mapgen_simplex_dropdown(rct_window *w, int widgetIndex, int d
 		break;
 	case WIDX_SIMPLEX_WALL_TEXTURE:
 		if (dropdownIndex == -1)
-			dropdownIndex = RCT2_GLOBAL(0x009DEBA2, sint16);
+			dropdownIndex = gDropdownHighlightedIndex;
 
 		type = (dropdownIndex == -1) ?
 		_wallTexture :
diff --git a/src/windows/options.c b/src/windows/options.c
index 301843995c..5567922add 100644
--- a/src/windows/options.c
+++ b/src/windows/options.c
@@ -715,8 +715,9 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 
 			window_options_show_dropdown(w, widget, gNumResolutions);
 
-			if (selectedResolution != -1 && selectedResolution < 32)
-				gDropdownItemsChecked = 1 << selectedResolution;
+			if (selectedResolution != -1 && selectedResolution < 32) {
+				dropdown_set_checked(selectedResolution, true);
+			}
 		}
 
 		break;
@@ -730,7 +731,7 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 
 			window_options_show_dropdown(w, widget, 3);
 
-			gDropdownItemsChecked = 1 << gConfigGeneral.fullscreen_mode;
+			dropdown_set_checked(gConfigGeneral.fullscreen_mode, true);
 			break;
 		case WIDX_CONSTRUCTION_MARKER_DROPDOWN:
 			gDropdownItemsFormat[0] = 1142;
@@ -740,7 +741,7 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 
 			window_options_show_dropdown(w, widget, 2);
 
-			gDropdownItemsChecked = 1 << gConfigGeneral.construction_marker_colour;
+			dropdown_set_checked(gConfigGeneral.construction_marker_colour, true);
 			break;
 		}
 		break;
@@ -755,7 +756,7 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 
 			window_options_show_dropdown(w, widget, 2);
 
-			gDropdownItemsChecked = gConfigGeneral.show_height_as_units ? 1 : 2;
+			dropdown_set_checked(gConfigGeneral.show_height_as_units ? 1 : 2, true);
 			break;
 		case WIDX_CURRENCY_DROPDOWN:
 			num_items = 10;
@@ -767,7 +768,7 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 
 			window_options_show_dropdown(w, widget, num_items);
 
-			gDropdownItemsChecked = 1 << gConfigGeneral.currency_format;
+			dropdown_set_checked(gConfigGeneral.currency_format, true);
 			break;
 		case WIDX_DISTANCE_DROPDOWN:
 			gDropdownItemsFormat[0] = 1142;
@@ -777,7 +778,7 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 
 			window_options_show_dropdown(w, widget, 2);
 
-			gDropdownItemsChecked = 1 << gConfigGeneral.measurement_format;
+			dropdown_set_checked(gConfigGeneral.measurement_format, true);
 			break;
 		case WIDX_TEMPERATURE_DROPDOWN:
 			gDropdownItemsFormat[0] = 1142;
@@ -787,7 +788,7 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 
 			window_options_show_dropdown(w, widget, 2);
 
-			gDropdownItemsChecked = 1 << gConfigGeneral.temperature_format;
+			dropdown_set_checked(gConfigGeneral.temperature_format, true);
 			break;
 		case WIDX_LANGUAGE_DROPDOWN:
 			for (i = 1; i < LANGUAGE_COUNT; i++) {
@@ -795,7 +796,7 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 				gDropdownItemsArgs[i - 1] = (sint32)LanguagesDescriptors[i].native_name;
 			}
 			window_options_show_dropdown(w, widget, LANGUAGE_COUNT - 1);
-			gDropdownItemsChecked = 1 << (gCurrentLanguage - 1);
+			dropdown_set_checked(gCurrentLanguage - 1, true);
 			break;
 		case WIDX_DATE_FORMAT_DROPDOWN:
 			for (i = 0; i < 4; i++) {
@@ -803,7 +804,7 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 				gDropdownItemsArgs[i] = DateFormatStringIds[i];
 			}
 			window_options_show_dropdown(w, widget, 4);
-			gDropdownItemsChecked = 1 << (gConfigGeneral.date_format);
+			dropdown_set_checked(gConfigGeneral.date_format, true);
 			break;
 		}
 		break;
@@ -821,7 +822,7 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 
 			window_options_show_dropdown(w, widget, gAudioDeviceCount);
 
-			gDropdownItemsChecked |= (1 << RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_SOUND_DEVICE, uint32));
+			dropdown_set_checked(RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_SOUND_DEVICE, uint32), true);
 			break;
 		case WIDX_TITLE_MUSIC_DROPDOWN:
 			num_items = 4;
@@ -836,7 +837,7 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 
 			window_options_show_dropdown(w, widget, num_items);
 
-			gDropdownItemsChecked = 1 << gConfigSound.title_music;
+			dropdown_set_checked(gConfigSound.title_music, true);
 			break;
 		}
 		break;
@@ -866,10 +867,11 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 				widget->right - widget->left - 3
 				);
 
-			if (gCurrentTheme == 0 || gCurrentTheme == 1)
-				gDropdownItemsChecked = 1 << (gCurrentTheme ^ 1);
-			else
-				gDropdownItemsChecked = 1 << (gCurrentTheme);
+			if (gCurrentTheme == 0 || gCurrentTheme == 1) {
+				dropdown_set_checked(gCurrentTheme ^ 1, true);
+			} else {
+				dropdown_set_checked(gCurrentTheme, true);
+			}
 			break;
 		}
 		break;
@@ -883,7 +885,7 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 			}
 
 			window_options_show_dropdown(w, widget, AUTOSAVE_NEVER + 1);
-			gDropdownItemsChecked = 1 << gConfigGeneral.autosave_frequency;
+			dropdown_set_checked(gConfigGeneral.autosave_frequency, true);
 			break;
 		case WIDX_TITLE_SEQUENCE_DROPDOWN:
 			num_items = gConfigTitleSequences.num_presets;
@@ -903,7 +905,7 @@ static void window_options_mousedown(int widgetIndex, rct_window*w, rct_widget*
 				widget->right - widget->left - 3
 				);
 
-			gDropdownItemsChecked = 1 << (gCurrentPreviewTitleSequence);
+			dropdown_set_checked(gCurrentPreviewTitleSequence, true);
 			break;
 		}
 		break;
diff --git a/src/windows/park.c b/src/windows/park.c
index 230160f55e..c4d4e0998d 100644
--- a/src/windows/park.c
+++ b/src/windows/park.c
@@ -689,11 +689,11 @@ static void window_park_entrance_mousedown(int widgetIndex, rct_window*w, rct_wi
 		);
 
 		if (park_is_open()) {
-			RCT2_GLOBAL(0x009DEBA2, sint16) = 0;
-			gDropdownItemsChecked |= (1 << 1);
+			gDropdownHighlightedIndex = 0;
+			dropdown_set_checked(1, true);
 		} else {
-			RCT2_GLOBAL(0x009DEBA2, sint16) = 1;
-			gDropdownItemsChecked |= (1 << 0);
+			gDropdownHighlightedIndex = 1;
+			dropdown_set_checked(0, true);
 		}
 	}
 }
@@ -706,7 +706,7 @@ static void window_park_entrance_dropdown(rct_window *w, int widgetIndex, int dr
 {
 	if (widgetIndex == WIDX_OPEN_OR_CLOSE) {
 		if (dropdownIndex == -1)
-			dropdownIndex = RCT2_GLOBAL(0x009DEBA2, sint16);
+			dropdownIndex = gDropdownHighlightedIndex;
 
 		if (dropdownIndex != 0) {
 			RCT2_GLOBAL(RCT2_ADDRESS_GAME_COMMAND_ERROR_TITLE, uint16) = 1724;
diff --git a/src/windows/research.c b/src/windows/research.c
index b888096b81..c58ce270ec 100644
--- a/src/windows/research.c
+++ b/src/windows/research.c
@@ -465,7 +465,7 @@ static void window_research_funding_mousedown(int widgetIndex, rct_window *w, rc
 	);
 
 	int currentResearchLevel = RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_RESEARCH_LEVEL, uint8);
-	gDropdownItemsChecked = (1 << currentResearchLevel);
+	dropdown_set_checked(currentResearchLevel, true);
 }
 
 /**
diff --git a/src/windows/ride.c b/src/windows/ride.c
index d6a99ea1cb..f757342726 100644
--- a/src/windows/ride.c
+++ b/src/windows/ride.c
@@ -1769,7 +1769,7 @@ static void window_ride_show_view_dropdown(rct_window *w, rct_widget *widget)
 	}
 
 	// Set checked item
-	gDropdownItemsChecked |= (1 << w->ride.view);
+	dropdown_set_checked(w->ride.view, true);
 }
 
 /**
@@ -1844,8 +1844,8 @@ static void window_ride_show_open_dropdown(rct_window *w, rct_widget *widget)
 			highlightedIndex--;
 	}
 
-	gDropdownItemsChecked |= (1 << checkedIndex);
-	RCT2_GLOBAL(0x009DEBA2, sint16) = highlightedIndex;
+	dropdown_set_checked(checkedIndex, true);
+	gDropdownHighlightedIndex = highlightedIndex;
 }
 
 /**
@@ -1892,7 +1892,7 @@ static void window_ride_main_dropdown(rct_window *w, int widgetIndex, int dropdo
 		break;
 	case WIDX_OPEN:
 		if (dropdownIndex == -1)
-			dropdownIndex = RCT2_GLOBAL(0x009DEBA2, sint16);
+			dropdownIndex = gDropdownHighlightedIndex;
 
 		ride = GET_RIDE(w->number);
 		if (ride_type_has_flag(ride->type, RIDE_TYPE_FLAG_NO_TEST_MODE) && dropdownIndex != 0)
@@ -2380,7 +2380,7 @@ static void window_ride_vehicle_mousedown(int widgetIndex, rct_window *w, rct_wi
 			widget->right - dropdownWidget->left
 		);
 
-		gDropdownItemsChecked = (1ULL << selectedIndex);
+		dropdown_set_checked(selectedIndex, true);
 		break;
 	case WIDX_VEHICLE_TRAINS_DROPDOWN:
 		window_dropdown_show_text_custom_width(
@@ -2399,7 +2399,7 @@ static void window_ride_vehicle_mousedown(int widgetIndex, rct_window *w, rct_wi
 			gDropdownItemsArgs[i] = ((i + 1) << 16) | (i == 0 ? stringId : stringId + 1);
 		}
 
-		gDropdownItemsChecked = (1 << (ride->num_vehicles - 1));
+		dropdown_set_checked(ride->num_vehicles - 1, true);
 		break;
 	case WIDX_VEHICLE_CARS_PER_TRAIN_DROPDOWN:
 		minCars = (ride->min_max_cars_per_train >> 4);
@@ -2425,7 +2425,7 @@ static void window_ride_vehicle_mousedown(int widgetIndex, rct_window *w, rct_wi
 			gDropdownItemsArgs[i] |= (cars - rideEntry->zero_cars) << 16;
 		}
 
-		gDropdownItemsChecked = (1 << (ride->num_cars_per_train - minCars));
+		dropdown_set_checked(ride->num_cars_per_train - minCars, true);
 		break;
 	}
 }
@@ -2820,9 +2820,11 @@ static void window_ride_mode_dropdown(rct_window *w, rct_widget *widget)
 	);
 
 	// Set checked item
-	for (i = 0; i < numAvailableModes; i++)
-		if (ride->mode == availableModes[i])
-			gDropdownItemsChecked = 1 << i;
+	for (i = 0; i < numAvailableModes; i++) {
+		if (ride->mode == availableModes[i]) {
+			dropdown_set_checked(i, true);
+		}
+	}
 }
 
 /**
@@ -2851,7 +2853,7 @@ static void window_ride_load_dropdown(rct_window *w, rct_widget *widget)
 		widget->right - dropdownWidget->left
 	);
 
-	gDropdownItemsChecked = (1 << (ride->depart_flags & RIDE_DEPART_WAIT_FOR_LOAD_MASK));
+	dropdown_set_checked(ride->depart_flags & RIDE_DEPART_WAIT_FOR_LOAD_MASK, true);
 }
 
 /**
@@ -3366,7 +3368,7 @@ static void window_ride_maintenance_mousedown(int widgetIndex, rct_window *w, rc
 			widget->right - dropdownWidget->left
 		);
 
-		gDropdownItemsChecked = (1 << ride->inspection_interval);
+		dropdown_set_checked(ride->inspection_interval, true);
 		break;
 
 	case WIDX_FORCE_BREAKDOWN:
@@ -3411,7 +3413,7 @@ static void window_ride_maintenance_mousedown(int widgetIndex, rct_window *w, rc
 								continue;
 						}
 						if (i == breakdownReason) {
-							gDropdownItemsChecked = (1 << num_items);
+							dropdown_set_checked(num_items, true);
 							break;
 						}
 						gDropdownItemsFormat[num_items] = 1142;
@@ -3813,7 +3815,7 @@ static void window_ride_colour_mousedown(int widgetIndex, rct_window *w, rct_wid
 			widget->right - dropdownWidget->left
 		);
 
-		gDropdownItemsChecked = 1 << colourSchemeIndex;
+		dropdown_set_checked(colourSchemeIndex, true);
 		break;
 	case WIDX_TRACK_MAIN_COLOUR:
 		window_dropdown_show_colour(w, widget, w->colours[1], ride->track_colour_main[colourSchemeIndex]);
@@ -3840,17 +3842,18 @@ static void window_ride_colour_mousedown(int widgetIndex, rct_window *w, rct_wid
 			widget->right - dropdownWidget->left
 		);
 
-		gDropdownItemsChecked = 1 << ride->track_colour_supports[colourSchemeIndex];
+		dropdown_set_checked(ride->track_colour_supports[colourSchemeIndex], true);
 		break;
-	case WIDX_ENTRANCE_STYLE_DROPDOWN:		
+	case WIDX_ENTRANCE_STYLE_DROPDOWN:
 		for (i = 0; i < countof(window_ride_entrance_style_list); i++) {
 			gDropdownItemsFormat[i] = 1142;
 			gDropdownItemsArgs[i] = RideEntranceDefinitions[window_ride_entrance_style_list[i]].string_id;
 
-			if (ride->entrance_style == window_ride_entrance_style_list[i])
-				gDropdownItemsChecked = 1 << i;
+			if (ride->entrance_style == window_ride_entrance_style_list[i]) {
+				dropdown_set_checked(i, true);
+			}
 		}
-		int checked = gDropdownItemsChecked;
+		uint64 checked = gDropdownItemsChecked;
 
 		window_dropdown_show_text_custom_width(
 			w->x + dropdownWidget->left,
@@ -3864,7 +3867,7 @@ static void window_ride_colour_mousedown(int widgetIndex, rct_window *w, rct_wid
 
 		gDropdownItemsChecked = checked;
 		break;
-	case WIDX_VEHICLE_COLOUR_SCHEME_DROPDOWN:		
+	case WIDX_VEHICLE_COLOUR_SCHEME_DROPDOWN:
 		for (i = 0; i < 3; i++) {
 			gDropdownItemsFormat[i] = 1142;
 			gDropdownItemsArgs[i] = (RideNameConvention[ride->type].vehicle_name << 16) | (STR_ALL_VEHICLES_IN_SAME_COLOURS + i);
@@ -3880,7 +3883,7 @@ static void window_ride_colour_mousedown(int widgetIndex, rct_window *w, rct_wid
 			widget->right - dropdownWidget->left
 		);
 
-		gDropdownItemsChecked = 1 << (ride->colour_scheme_type & 3);
+		dropdown_set_checked(ride->colour_scheme_type & 3, true);
 		break;
 	case WIDX_VEHICLE_COLOUR_INDEX_DROPDOWN:
 		numItems = ride->num_vehicles;
@@ -3903,7 +3906,7 @@ static void window_ride_colour_mousedown(int widgetIndex, rct_window *w, rct_wid
 			widget->right - dropdownWidget->left
 		);
 
-		gDropdownItemsChecked = 1 << w->var_48C;
+		dropdown_set_checked(w->var_48C, true);
 		break;
 	case WIDX_VEHICLE_MAIN_COLOUR:
 		vehicleColour = ride_get_vehicle_colour(ride, w->var_48C);
@@ -4452,8 +4455,9 @@ static void window_ride_music_mousedown(int widgetIndex, rct_window *w, rct_widg
 	);
 
 	for (i = 0; i < numItems; i++) {
-		if (window_ride_current_music_style_order[i] == ride->music)
-			gDropdownItemsChecked = (1 << i);
+		if (window_ride_current_music_style_order[i] == ride->music) {
+			dropdown_set_checked(i, true);
+		}
 	}
 }
 
@@ -4702,7 +4706,7 @@ static void window_ride_measurements_mousedown(int widgetIndex, rct_window *w, r
 		0,
 		2
 	);
-	RCT2_GLOBAL(0x009DEBA2, sint16) = 0;
+	gDropdownHighlightedIndex = 0;
 	if (RCT2_GLOBAL(RCT2_ADDRESS_SCREEN_FLAGS, uint8) & SCREEN_FLAGS_TRACK_DESIGNER)
 		gDropdownItemsDisabled |= 2;
 }
@@ -4717,7 +4721,7 @@ static void window_ride_measurements_dropdown(rct_window *w, int widgetIndex, in
 		return;
 
 	if (dropdownIndex == -1)
-		dropdownIndex = RCT2_GLOBAL(0x009DEBA2, sint16);
+		dropdownIndex = gDropdownHighlightedIndex;
 
 	if (dropdownIndex == 0)
 		save_track_design((uint8)w->number);
diff --git a/src/windows/ride_construction.c b/src/windows/ride_construction.c
index 91d47ad76f..6257ecf9ad 100644
--- a/src/windows/ride_construction.c
+++ b/src/windows/ride_construction.c
@@ -3161,7 +3161,7 @@ static void window_ride_construction_show_special_track_dropdown(rct_window *w,
 		}
 		gDropdownItemsFormat[i] = trackPieceStringId;
 		if ((trackPiece | 0x100) == _currentTrackCurve) {
-			RCT2_GLOBAL(0x009DEBA2, sint16) = i;
+			gDropdownHighlightedIndex = i;
 		}
 	}
 
diff --git a/src/windows/ride_list.c b/src/windows/ride_list.c
index 873a93c76e..ae3cf98b2d 100644
--- a/src/windows/ride_list.c
+++ b/src/windows/ride_list.c
@@ -263,7 +263,7 @@ static void window_ride_list_mousedown(int widgetIndex, rct_window*w, rct_widget
 			numItems,
 			widget->right - widget->left - 3
 		);
-		gDropdownItemsChecked |= (1 << _window_ride_list_information_type);
+		dropdown_set_checked(_window_ride_list_information_type, true);
 	}
 }
 
diff --git a/src/windows/staff.c b/src/windows/staff.c
index 423564f341..4b306cf126 100644
--- a/src/windows/staff.c
+++ b/src/windows/staff.c
@@ -532,7 +532,7 @@ void window_staff_overview_mousedown(int widgetIndex, rct_window* w, rct_widget*
 	int y = widget->top + w->y;
 	int extray = widget->bottom - widget->top + 1;
 	window_dropdown_show_text(x, y, extray, w->colours[1], 0, 2);
-	RCT2_GLOBAL(0x009DEBA2, sint16) = 0;
+	gDropdownHighlightedIndex = 0;
 
 	rct_peep* peep = GET_PEEP(w->number);
 
diff --git a/src/windows/themes.c b/src/windows/themes.c
index 3c51d80887..94b04f68a9 100644
--- a/src/windows/themes.c
+++ b/src/windows/themes.c
@@ -552,10 +552,11 @@ static void window_themes_mousedown(int widgetIndex, rct_window* w, rct_widget*
 			widget->right - widget->left - 3
 			);
 
-		if (gCurrentTheme == 0 || gCurrentTheme == 1)
-			gDropdownItemsChecked = 1 << (gCurrentTheme ^ 1);
-		else
-			gDropdownItemsChecked = 1 << (gCurrentTheme);
+		if (gCurrentTheme == 0 || gCurrentTheme == 1) {
+			dropdown_set_checked(gCurrentTheme ^ 1, true);
+		} else {
+			dropdown_set_checked(gCurrentTheme, true);
+		}
 		break;
 	case WIDX_THEMES_RCT1_RIDE_LIGHTS:
 		if (gCurrentTheme >= 2) {
diff --git a/src/windows/title_command_editor.c b/src/windows/title_command_editor.c
index 54e74ce8ee..7fb1c66aca 100644
--- a/src/windows/title_command_editor.c
+++ b/src/windows/title_command_editor.c
@@ -322,7 +322,7 @@ static void window_title_command_editor_mousedown(int widgetIndex, rct_window* w
 			widget->right - widget->left - 3
 			);
 
-		gDropdownItemsChecked = 1 << get_command_info_index(command.command);
+		dropdown_set_checked(get_command_info_index(command.command), true);
 		break;
 	case WIDX_INPUT_DROPDOWN:
 		if (command.command == TITLE_SCRIPT_SPEED) {
@@ -342,7 +342,7 @@ static void window_title_command_editor_mousedown(int widgetIndex, rct_window* w
 				widget->right - widget->left - 3
 				);
 
-			gDropdownItemsChecked = 1 << (command.speed - 1);
+			dropdown_set_checked(command.speed - 1, true);
 		}
 		else if (command.command == TITLE_SCRIPT_LOAD) {
 			num_items = gConfigTitleSequences.presets[gCurrentTitleSequence].num_saves;
@@ -361,7 +361,7 @@ static void window_title_command_editor_mousedown(int widgetIndex, rct_window* w
 				widget->right - widget->left - 3
 				);
 
-			gDropdownItemsChecked = 1 << (command.saveIndex);
+			dropdown_set_checked(command.saveIndex, true);
 		}
 		break;
 	}
diff --git a/src/windows/title_editor.c b/src/windows/title_editor.c
index feb68f79e0..5832f8c17d 100644
--- a/src/windows/title_editor.c
+++ b/src/windows/title_editor.c
@@ -587,7 +587,7 @@ static void window_title_editor_mousedown(int widgetIndex, rct_window* w, rct_wi
 				widget->right - widget->left - 3
 				);
 
-			gDropdownItemsChecked = 1 << (gCurrentTitleSequence);
+			dropdown_set_checked(gCurrentTitleSequence, true);
 		}
 		break;
 	}
diff --git a/src/windows/top_toolbar.c b/src/windows/top_toolbar.c
index 868068e110..1b01e3361f 100644
--- a/src/windows/top_toolbar.c
+++ b/src/windows/top_toolbar.c
@@ -411,8 +411,9 @@ static void window_top_toolbar_mousedown(int widgetIndex, rct_window*w, rct_widg
 		);
 
 #ifndef DISABLE_TWITCH
-		if (_menuDropdownIncludesTwitch && gTwitchEnable)
-			gDropdownItemsChecked |= (1 << 11);
+		if (_menuDropdownIncludesTwitch && gTwitchEnable) {
+			dropdown_set_checked(11, true);
+		}
 #endif
 		break;
 	case WIDX_CHEATS:
@@ -433,12 +434,15 @@ static void window_top_toolbar_mousedown(int widgetIndex, rct_window*w, rct_widg
 			0,
 			5
 		);
-		if (gCheatsSandboxMode)
-			gDropdownItemsChecked |= (1 << DDIDX_ENABLE_SANDBOX_MODE);
-		if (gCheatsDisableClearanceChecks)
-			gDropdownItemsChecked |= (1 << DDIDX_DISABLE_CLEARANCE_CHECKS);
-		if (gCheatsDisableSupportLimits)
-			gDropdownItemsChecked |= (1 << DDIDX_DISABLE_SUPPORT_LIMITS);
+		if (gCheatsSandboxMode) {
+			dropdown_set_checked(DDIDX_ENABLE_SANDBOX_MODE, true);
+		}
+		if (gCheatsDisableClearanceChecks) {
+			dropdown_set_checked(DDIDX_DISABLE_CLEARANCE_CHECKS, true);
+		}
+		if (gCheatsDisableSupportLimits) {
+			dropdown_set_checked(DDIDX_DISABLE_SUPPORT_LIMITS, true);
+		}
 		RCT2_GLOBAL(0x009DEBA2, uint16) = 0;
 		break;
 	case WIDX_VIEW_MENU:
@@ -2844,10 +2848,12 @@ void top_toolbar_init_fastforward_menu(rct_window* w, rct_widget* widget) {
 		);
 
 	// Set checkmarks
-	if (gGameSpeed <= 4)
-		gDropdownItemsChecked |= (1 << (gGameSpeed - 1));
-	if (gGameSpeed == 8)
-		gDropdownItemsChecked |= (1 << 5);
+	if (gGameSpeed <= 4) {
+		dropdown_set_checked(gGameSpeed - 1, true);
+	}
+	if (gGameSpeed == 8) {
+		dropdown_set_checked(5, true);
+	}
 
 	if (gConfigGeneral.debugging_tools)
 		RCT2_GLOBAL(0x9DEBA2, uint16) = (gGameSpeed == 8 ? 0 : gGameSpeed);
@@ -3011,25 +3017,25 @@ void top_toolbar_init_view_menu(rct_window* w, rct_widget* widget) {
 	// Set checkmarks
 	rct_viewport* mainViewport = window_get_main()->viewport;
 	if (mainViewport->flags & VIEWPORT_FLAG_UNDERGROUND_INSIDE)
-		gDropdownItemsChecked |= (1 << 0);
+		dropdown_set_checked(0, true);
 	if (mainViewport->flags & VIEWPORT_FLAG_HIDE_BASE)
-		gDropdownItemsChecked |= (1 << 1);
+		dropdown_set_checked(1, true);
 	if (mainViewport->flags & VIEWPORT_FLAG_HIDE_VERTICAL)
-		gDropdownItemsChecked |= (1 << 2);
+		dropdown_set_checked(2, true);
 	if (mainViewport->flags & VIEWPORT_FLAG_SEETHROUGH_RIDES)
-		gDropdownItemsChecked |= (1 << 4);
+		dropdown_set_checked(4, true);
 	if (mainViewport->flags & VIEWPORT_FLAG_SEETHROUGH_SCENERY)
-		gDropdownItemsChecked |= (1 << 5);
+		dropdown_set_checked(5, true);
 	if (mainViewport->flags & VIEWPORT_FLAG_INVISIBLE_SUPPORTS)
-		gDropdownItemsChecked |= (1 << 6);
+		dropdown_set_checked(6, true);
 	if (mainViewport->flags & VIEWPORT_FLAG_INVISIBLE_PEEPS)
-		gDropdownItemsChecked |= (1 << 7);
+		dropdown_set_checked(7, true);
 	if (mainViewport->flags & VIEWPORT_FLAG_LAND_HEIGHTS)
-		gDropdownItemsChecked |= (1 << 9);
+		dropdown_set_checked(9, true);
 	if (mainViewport->flags & VIEWPORT_FLAG_TRACK_HEIGHTS)
-		gDropdownItemsChecked |= (1 << 10);
+		dropdown_set_checked(10, true);
 	if (mainViewport->flags & VIEWPORT_FLAG_PATH_HEIGHTS)
-		gDropdownItemsChecked |= (1 << 11);
+		dropdown_set_checked(11, true);
 
 	RCT2_GLOBAL(0x9DEBA2, uint16) = 0;
 }