diff --git a/src/openrct2/world/Banner.cpp b/src/openrct2/world/Banner.cpp
index f8502445f9..ee815656a4 100644
--- a/src/openrct2/world/Banner.cpp
+++ b/src/openrct2/world/Banner.cpp
@@ -232,7 +232,7 @@ static money32 BannerPlace(
     }
 
     *bannerIndex = create_new_banner(flags);
-    if (*bannerIndex == BANNER_NULL)
+    if (*bannerIndex == BANNER_INDEX_NULL)
     {
         return MONEY32_UNDEFINED;
     }
@@ -505,7 +505,7 @@ void fix_duplicated_banners()
 
                         // Banner index is already in use by another banner, so duplicate it
                         BannerIndex newBannerIndex = create_new_banner(GAME_COMMAND_FLAG_APPLY);
-                        if (newBannerIndex == BANNER_NULL)
+                        if (newBannerIndex == BANNER_INDEX_NULL)
                         {
                             log_error("Failed to create new banner.");
                             continue;
diff --git a/src/openrct2/world/Banner.h b/src/openrct2/world/Banner.h
index 0a88789f8a..0993107d00 100644
--- a/src/openrct2/world/Banner.h
+++ b/src/openrct2/world/Banner.h
@@ -14,15 +14,14 @@
  *****************************************************************************/
 #pragma endregion
 
-#ifndef _BANNER_H_
-#define _BANNER_H_
+#pragma once
 
 #include "../common.h"
 #include "TileElement.h"
 
-#define BANNER_NULL 255
-#define MAX_BANNERS 250
-#define BANNER_INDEX_NULL ((BannerIndex)-1)
+constexpr uint8 BANNER_NULL = 255;
+constexpr size_t MAX_BANNERS = 250;
+constexpr BannerIndex BANNER_INDEX_NULL = (BannerIndex)-1;
 
 #pragma pack(push, 1)
 struct rct_banner
@@ -59,5 +58,3 @@ uint8 banner_get_closest_ride_index(sint32 x, sint32 y, sint32 z);
 void banner_reset_broken_index();
 void fix_duplicated_banners();
 void game_command_callback_place_banner(sint32 eax, sint32 ebx, sint32 ecx, sint32 edx, sint32 esi, sint32 edi, sint32 ebp);
-
-#endif
diff --git a/src/openrct2/world/TileInspector.cpp b/src/openrct2/world/TileInspector.cpp
index ccdf8c8d6e..7e4d91e0cd 100644
--- a/src/openrct2/world/TileInspector.cpp
+++ b/src/openrct2/world/TileInspector.cpp
@@ -309,7 +309,7 @@ sint32 tile_inspector_paste_element_at(sint32 x, sint32 y, rct_tile_element elem
         {
             // The element to be pasted refers to a banner index - make a copy of it
             BannerIndex newBannerIndex = create_new_banner(flags);
-            if (newBannerIndex == BANNER_NULL)
+            if (newBannerIndex == BANNER_INDEX_NULL)
             {
                 return MONEY32_UNDEFINED;
             }