diff --git a/src/openrct2-ui/windows/Scenery.cpp b/src/openrct2-ui/windows/Scenery.cpp
index 64df5ac8a1..f174861160 100644
--- a/src/openrct2-ui/windows/Scenery.cpp
+++ b/src/openrct2-ui/windows/Scenery.cpp
@@ -197,7 +197,7 @@ static ScenerySelection window_scenery_tab_entries[SCENERY_WINDOW_TABS][SCENERY_
  * Was part of 0x006DFA00
  * The same code repeated five times for every scenery entry type
  */
-static void init_scenery_entry(rct_scenery_entry* sceneryEntry, ScenerySelection index, uint8_t sceneryTabId)
+static void init_scenery_entry(rct_scenery_entry* sceneryEntry, const ScenerySelection& index, uint8_t sceneryTabId)
 {
     Guard::ArgumentInRange<int32_t>(index.EntryIndex, 0, WINDOW_SCENERY_TAB_SELECTION_UNDEFINED);
     if (scenery_is_invented(index) || gCheatsIgnoreResearchStatus)
@@ -1353,7 +1353,7 @@ void window_scenery_scrollpaint(rct_window* w, rct_drawpixelinfo* dpi, int32_t s
     }
 }
 
-static int32_t window_scenery_find_tab_with_scenery(ScenerySelection scenery)
+static int32_t window_scenery_find_tab_with_scenery(const ScenerySelection& scenery)
 {
     for (int32_t i = 0; i < SCENERY_WINDOW_TABS; i++)
     {
@@ -1369,7 +1369,7 @@ static int32_t window_scenery_find_tab_with_scenery(ScenerySelection scenery)
     return -1;
 }
 
-bool window_scenery_set_selected_item(ScenerySelection scenery)
+bool window_scenery_set_selected_item(const ScenerySelection& scenery)
 {
     bool result = false;
     rct_window* w = window_bring_to_front_by_class(WC_SCENERY);
diff --git a/src/openrct2-ui/windows/Window.h b/src/openrct2-ui/windows/Window.h
index 7f03b54cd3..a0f7158634 100644
--- a/src/openrct2-ui/windows/Window.h
+++ b/src/openrct2-ui/windows/Window.h
@@ -164,7 +164,7 @@ bool clear_scenery_tool_is_active();
 bool water_tool_is_active();
 
 rct_window* window_scenery_open();
-bool window_scenery_set_selected_item(ScenerySelection scenery);
+bool window_scenery_set_selected_item(const ScenerySelection& scenery);
 void window_scenery_set_default_placement_configuration();
 void window_scenery_init();
 void window_scenery_reset_selected_scenery_items();
diff --git a/src/openrct2/management/Research.cpp b/src/openrct2/management/Research.cpp
index 5d28275c74..801e346dcb 100644
--- a/src/openrct2/management/Research.cpp
+++ b/src/openrct2/management/Research.cpp
@@ -599,17 +599,17 @@ void ride_entry_set_invented(int32_t rideEntryIndex)
     _researchedRideEntries[rideEntryIndex] = true;
 }
 
-bool scenery_is_invented(ScenerySelection sceneryItem)
+bool scenery_is_invented(const ScenerySelection& sceneryItem)
 {
     return _researchedSceneryItems[sceneryItem.SceneryType][sceneryItem.EntryIndex];
 }
 
-void scenery_set_invented(ScenerySelection sceneryItem)
+void scenery_set_invented(const ScenerySelection& sceneryItem)
 {
     _researchedSceneryItems[sceneryItem.SceneryType][sceneryItem.EntryIndex] = true;
 }
 
-void scenery_set_not_invented(ScenerySelection sceneryItem)
+void scenery_set_not_invented(const ScenerySelection& sceneryItem)
 {
     _researchedSceneryItems[sceneryItem.SceneryType][sceneryItem.EntryIndex] = false;
 }
diff --git a/src/openrct2/management/Research.h b/src/openrct2/management/Research.h
index 18e6a50dbd..8bc6342112 100644
--- a/src/openrct2/management/Research.h
+++ b/src/openrct2/management/Research.h
@@ -129,15 +129,15 @@ void research_insert_scenery_group_entry(uint8_t entryIndex, bool researched);
 
 void ride_type_set_invented(uint32_t rideType);
 void ride_entry_set_invented(int32_t rideEntryIndex);
-void scenery_set_invented(ScenerySelection sceneryItem);
-void scenery_set_not_invented(ScenerySelection sceneryItem);
+void scenery_set_invented(const ScenerySelection& sceneryItem);
+void scenery_set_not_invented(const ScenerySelection& sceneryItem);
 bool ride_type_is_invented(uint32_t rideType);
 bool ride_entry_is_invented(int32_t rideEntryIndex);
 uint64_t get_available_track_pieces_for_ride_type(uint8_t rideType);
 bool track_piece_is_available_for_ride_type(uint8_t rideType, int32_t trackType);
 bool scenery_group_is_invented(int32_t sgIndex);
 void scenery_group_set_invented(int32_t sgIndex);
-bool scenery_is_invented(ScenerySelection sceneryItem);
+bool scenery_is_invented(const ScenerySelection& sceneryItem);
 void set_all_scenery_items_invented();
 void set_all_scenery_items_not_invented();
 void set_all_scenery_groups_not_invented();