diff --git a/include/fieldmap.h b/include/fieldmap.h
index 65ab57a1e..a23b6c428 100644
--- a/include/fieldmap.h
+++ b/include/fieldmap.h
@@ -33,8 +33,8 @@ void GetCameraCoords(u16 *, u16 *);
 bool8 MapGridGetCollisionAt(s32, s32);
 s32 GetMapBorderIdAt(s32, s32);
 bool32 CanCameraMoveInDirection(s32);
-const struct MapHeader * GetMapHeaderFromConnection(struct MapConnection * connection);
-struct MapConnection * GetMapConnectionAtPos(s16 x, s16 y);
+const struct MapHeader * GetMapHeaderFromConnection(const struct MapConnection * connection);
+const struct MapConnection * GetMapConnectionAtPos(s16 x, s16 y);
 void ApplyGlobalTintToPaletteSlot(u8 slot, u8 count);
 void SaveMapView(void);
 u32 ExtractMetatileAttribute(u32 attributes, u8 attributeType);
diff --git a/include/global.fieldmap.h b/include/global.fieldmap.h
index dad5e1d62..e2828ec0c 100644
--- a/include/global.fieldmap.h
+++ b/include/global.fieldmap.h
@@ -92,10 +92,10 @@ struct MapLayout
 {
     /*0x00*/ s32 width;
     /*0x04*/ s32 height;
-    /*0x08*/ u16 *border;
-    /*0x0c*/ u16 *map;
-    /*0x10*/ struct Tileset *primaryTileset;
-    /*0x14*/ struct Tileset *secondaryTileset;
+    /*0x08*/ const u16 *border;
+    /*0x0c*/ const u16 *map;
+    /*0x10*/ const struct Tileset *primaryTileset;
+    /*0x14*/ const struct Tileset *secondaryTileset;
     /*0x18*/ u8 borderWidth;
     /*0x19*/ u8 borderHeight;
 };
@@ -148,7 +148,7 @@ struct CoordEvent
     u8 elevation;
     u16 trigger;
     u16 index;
-    u8 *script;
+    const u8 *script;
 };
 
 struct BgEvent
@@ -157,7 +157,7 @@ struct BgEvent
     u8 elevation;
     u8 kind; // The "kind" field determines how to access bgUnion union below.
     union {
-        u8 *script;
+        const u8 *script;
         u32 hiddenItem; // Contains all the hidden item data. See GET_HIDDEN_ITEM_* defines further up
     } bgUnion;
 };
@@ -168,10 +168,10 @@ struct MapEvents
     u8 warpCount;
     u8 coordEventCount;
     u8 bgEventCount;
-    struct ObjectEventTemplate *objectEvents;
-    struct WarpEvent *warps;
-    struct CoordEvent *coordEvents;
-    struct BgEvent *bgEvents;
+    const struct ObjectEventTemplate *objectEvents;
+    const struct WarpEvent *warps;
+    const struct CoordEvent *coordEvents;
+    const struct BgEvent *bgEvents;
 };
 
 struct MapConnection
@@ -185,7 +185,7 @@ struct MapConnection
 struct MapConnections
 {
     s32 count;
-    struct MapConnection *connections;
+    const struct MapConnection *connections;
 };
 
 struct MapHeader
diff --git a/src/event_object_movement.c b/src/event_object_movement.c
index 0b3caa398..591574afc 100644
--- a/src/event_object_movement.c
+++ b/src/event_object_movement.c
@@ -67,9 +67,9 @@ static void SetObjectEventDynamicGraphicsId(struct ObjectEvent *);
 static void RemoveObjectEventInternal(struct ObjectEvent *);
 static u16 GetObjectEventFlagIdByObjectEventId(u8);
 static void UpdateObjectEventVisibility(struct ObjectEvent *, struct Sprite *);
-static void MakeObjectTemplateFromObjectEventTemplate(struct ObjectEventTemplate *, struct SpriteTemplate *, const struct SubspriteTable **);
+static void MakeObjectTemplateFromObjectEventTemplate(const struct ObjectEventTemplate *, struct SpriteTemplate *, const struct SubspriteTable **);
 static void GetObjectEventMovingCameraOffset(s16 *, s16 *);
-static struct ObjectEventTemplate *GetObjectEventTemplateByLocalIdAndMap(u8, u8, u8);
+static const struct ObjectEventTemplate *GetObjectEventTemplateByLocalIdAndMap(u8, u8, u8);
 static void LoadObjectEventPalette(u16);
 static void RemoveObjectEventIfOutsideView(struct ObjectEvent *);
 static void SpawnObjectEventOnReturnToField(u8 objectEventId, s16 x, s16 y);
@@ -84,13 +84,13 @@ static void ObjectCB_CameraObject(struct Sprite *);
 static void CameraObject_0(struct Sprite *);
 static void CameraObject_1(struct Sprite *);
 static void CameraObject_2(struct Sprite *);
-static struct ObjectEventTemplate *FindObjectEventTemplateByLocalId(u8 localId, struct ObjectEventTemplate *templates, u8 count);
+static const struct ObjectEventTemplate *FindObjectEventTemplateByLocalId(u8 localId, const struct ObjectEventTemplate *templates, u8 count);
 static void ClearObjectEventMovement(struct ObjectEvent *, struct Sprite *);
 static void ObjectEventSetSingleMovement(struct ObjectEvent *, struct Sprite *, u8);
-static bool8 ShouldInitObjectEventStateFromTemplate(struct ObjectEventTemplate *, u8, s16, s16);
-static bool8 TemplateIsObstacleAndWithinView(struct ObjectEventTemplate *, s16, s16);
-static bool8 TemplateIsObstacleAndVisibleFromConnectingMap(struct ObjectEventTemplate *, s16, s16);
-static void SetHideObstacleFlag(struct ObjectEventTemplate *);
+static bool8 ShouldInitObjectEventStateFromTemplate(const struct ObjectEventTemplate *, u8, s16, s16);
+static bool8 TemplateIsObstacleAndWithinView(const struct ObjectEventTemplate *, s16, s16);
+static bool8 TemplateIsObstacleAndVisibleFromConnectingMap(const struct ObjectEventTemplate *, s16, s16);
+static void SetHideObstacleFlag(const struct ObjectEventTemplate *);
 static bool8 MovementType_Disguise_Callback(struct ObjectEvent *, struct Sprite *);
 static bool8 MovementType_Buried_Callback(struct ObjectEvent *, struct Sprite *);
 static u8 MovementType_RaiseHandAndStop_Callback(struct ObjectEvent *, struct Sprite *);
@@ -1309,7 +1309,7 @@ static u8 GetObjectEventIdByLocalId(u8 localId)
     return OBJECT_EVENTS_COUNT;
 }
 
-static u8 InitObjectEventStateFromTemplate(struct ObjectEventTemplate *template, u8 mapNum, u8 mapGroup)
+static u8 InitObjectEventStateFromTemplate(const struct ObjectEventTemplate *template, u8 mapNum, u8 mapGroup)
 {
     struct ObjectEvent *objectEvent;
     const struct MapHeader *mapHeader;
@@ -1388,7 +1388,7 @@ static u8 InitObjectEventStateFromTemplate(struct ObjectEventTemplate *template,
     return objectEventId;
 }
 
-static bool8 ShouldInitObjectEventStateFromTemplate(struct ObjectEventTemplate *template, bool8 isClone, s16 x, s16 y)
+static bool8 ShouldInitObjectEventStateFromTemplate(const struct ObjectEventTemplate *template, bool8 isClone, s16 x, s16 y)
 {
     if (isClone && !TemplateIsObstacleAndWithinView(template, x, y))
         return FALSE;
@@ -1399,7 +1399,7 @@ static bool8 ShouldInitObjectEventStateFromTemplate(struct ObjectEventTemplate *
     return TRUE;
 }
 
-static bool8 TemplateIsObstacleAndWithinView(struct ObjectEventTemplate *template, s16 x, s16 y)
+static bool8 TemplateIsObstacleAndWithinView(const struct ObjectEventTemplate *template, s16 x, s16 y)
 {
     if (template->graphicsId == OBJ_EVENT_GFX_CUT_TREE || template->graphicsId == OBJ_EVENT_GFX_ROCK_SMASH_ROCK)
     {
@@ -1422,7 +1422,7 @@ static bool8 TemplateIsObstacleAndWithinView(struct ObjectEventTemplate *templat
     return TRUE;
 }
 
-static bool8 TemplateIsObstacleAndVisibleFromConnectingMap(struct ObjectEventTemplate *template, s16 unused1, s16 unused2)
+static bool8 TemplateIsObstacleAndVisibleFromConnectingMap(const struct ObjectEventTemplate *template, s16 unused1, s16 unused2)
 {
     if (IsMapTypeOutdoors(GetCurrentMapType()))
     {
@@ -1459,7 +1459,7 @@ static bool8 TemplateIsObstacleAndVisibleFromConnectingMap(struct ObjectEventTem
     return TRUE;
 }
 
-static void SetHideObstacleFlag(struct ObjectEventTemplate *template)
+static void SetHideObstacleFlag(const struct ObjectEventTemplate *template)
 {
     if (template->flagId >= FLAG_TEMP_11 && template->flagId <= FLAG_TEMP_1F)
         FlagSet(template->flagId);
@@ -1549,7 +1549,7 @@ void Unref_RemoveAllObjectEventsExceptPlayer(void)
     }
 }
 
-static u8 TrySetupObjectEventSprite(struct ObjectEventTemplate *objectEventTemplate, struct SpriteTemplate *spriteTemplate, u8 mapNum, u8 mapGroup, s16 cameraX, s16 cameraY)
+static u8 TrySetupObjectEventSprite(const struct ObjectEventTemplate *objectEventTemplate, struct SpriteTemplate *spriteTemplate, u8 mapNum, u8 mapGroup, s16 cameraX, s16 cameraY)
 {
     u8 spriteId;
     u8 objectEventId;
@@ -1599,7 +1599,7 @@ static u8 TrySetupObjectEventSprite(struct ObjectEventTemplate *objectEventTempl
     return objectEventId;
 }
 
-static u8 TrySpawnObjectEventTemplate(struct ObjectEventTemplate *objectEventTemplate, u8 mapNum, u8 mapGroup, s16 cameraX, s16 cameraY)
+static u8 TrySpawnObjectEventTemplate(const struct ObjectEventTemplate *objectEventTemplate, u8 mapNum, u8 mapGroup, s16 cameraX, s16 cameraY)
 {
     u8 objectEventId;
     struct SpriteTemplate spriteTemplate;
@@ -1653,7 +1653,7 @@ int SpawnSpecialObjectEventParameterized(u8 graphicsId, u8 movementBehavior, u8
 
 u8 TrySpawnObjectEvent(u8 localId, u8 mapNum, u8 mapGroup)
 {
-    struct ObjectEventTemplate *objectEventTemplate;
+    const struct ObjectEventTemplate *objectEventTemplate;
     s16 cameraX, cameraY;
 
     objectEventTemplate = GetObjectEventTemplateByLocalIdAndMap(localId, mapNum, mapGroup);
@@ -1691,7 +1691,7 @@ static void CopyObjectGraphicsInfoToSpriteTemplate_WithMovementType(u16 graphics
     CopyObjectGraphicsInfoToSpriteTemplate(graphicsId, sMovementTypeCallbacks[movementType], spriteTemplate, subspriteTables);
 }
 
-static void MakeObjectTemplateFromObjectEventTemplate(struct ObjectEventTemplate *objectEventTemplate, struct SpriteTemplate *spriteTemplate, const struct SubspriteTable **subspriteTables)
+static void MakeObjectTemplateFromObjectEventTemplate(const struct ObjectEventTemplate *objectEventTemplate, struct SpriteTemplate *spriteTemplate, const struct SubspriteTable **subspriteTables)
 {
     CopyObjectGraphicsInfoToSpriteTemplate_WithMovementType(objectEventTemplate->graphicsId, objectEventTemplate->objUnion.normal.movementType, spriteTemplate, subspriteTables);
 }
@@ -2516,7 +2516,7 @@ const u8 *GetObjectEventScriptPointerByObjectEventId(u8 objectEventId)
 
 static u16 GetObjectEventFlagIdByLocalIdAndMap(u8 localId, u8 mapNum, u8 mapGroup)
 {
-    struct ObjectEventTemplate *obj = GetObjectEventTemplateByLocalIdAndMap(localId, mapNum, mapGroup);
+    const struct ObjectEventTemplate *obj = GetObjectEventTemplateByLocalIdAndMap(localId, mapNum, mapGroup);
 #ifdef UBFIX
     // BUG: The function may return NULL, and attempting to read from NULL may freeze the game using modern compilers.
     if (obj == NULL)
@@ -2571,9 +2571,9 @@ u8 GetObjectEventBerryTreeId(u8 objectEventId)
     return gObjectEvents[objectEventId].trainerRange_berryTreeId;
 }
 
-static struct ObjectEventTemplate *GetObjectEventTemplateByLocalIdAndMap(u8 localId, u8 mapNum, u8 mapGroup)
+static const struct ObjectEventTemplate *GetObjectEventTemplateByLocalIdAndMap(u8 localId, u8 mapNum, u8 mapGroup)
 {
-    struct ObjectEventTemplate *templates;
+    const struct ObjectEventTemplate *templates;
     const struct MapHeader *mapHeader;
     u8 count;
 
@@ -2591,7 +2591,7 @@ static struct ObjectEventTemplate *GetObjectEventTemplateByLocalIdAndMap(u8 loca
     return FindObjectEventTemplateByLocalId(localId, templates, count);
 }
 
-static struct ObjectEventTemplate *FindObjectEventTemplateByLocalId(u8 localId, struct ObjectEventTemplate *templates, u8 count)
+static const struct ObjectEventTemplate *FindObjectEventTemplateByLocalId(u8 localId, const struct ObjectEventTemplate *templates, u8 count)
 {
     u8 i;
 
diff --git a/src/field_control_avatar.c b/src/field_control_avatar.c
index 1216bec21..41ef6ab9c 100644
--- a/src/field_control_avatar.c
+++ b/src/field_control_avatar.c
@@ -1008,7 +1008,7 @@ static bool8 TryDoorWarp(struct MapPosition *position, u16 metatileBehavior, u8
 static s8 GetWarpEventAtPosition(struct MapHeader *mapHeader, u16 x, u16 y, u8 elevation)
 {
     s32 i;
-    struct WarpEvent *warpEvent = mapHeader->events->warps;
+    const struct WarpEvent *warpEvent = mapHeader->events->warps;
     u8 warpCount = mapHeader->events->warpCount;
 
     for (i = 0; i < warpCount; i++, warpEvent++)
@@ -1022,7 +1022,7 @@ static s8 GetWarpEventAtPosition(struct MapHeader *mapHeader, u16 x, u16 y, u8 e
     return -1;
 }
 
-static const u8 *TryRunCoordEventScript(struct CoordEvent *coordEvent)
+static const u8 *TryRunCoordEventScript(const struct CoordEvent *coordEvent)
 {
     if (coordEvent != NULL)
     {
@@ -1045,7 +1045,7 @@ static const u8 *TryRunCoordEventScript(struct CoordEvent *coordEvent)
 static const u8 *GetCoordEventScriptAtPosition(struct MapHeader *mapHeader, u16 x, u16 y, u8 elevation)
 {
     s32 i;
-    struct CoordEvent *coordEvents = mapHeader->events->coordEvents;
+    const struct CoordEvent *coordEvents = mapHeader->events->coordEvents;
     u8 coordEventCount = mapHeader->events->coordEventCount;
 
     for (i = 0; i < coordEventCount; i++)
@@ -1101,7 +1101,7 @@ const u8 *GetCoordEventScriptAtMapPosition(struct MapPosition *position)
 static const struct BgEvent *GetBackgroundEventAtPosition(struct MapHeader *mapHeader, u16 x, u16 y, u8 elevation)
 {
     u8 i;
-    struct BgEvent *bgEvents = mapHeader->events->bgEvents;
+    const struct BgEvent *bgEvents = mapHeader->events->bgEvents;
     u8 bgEventCount = mapHeader->events->bgEventCount;
 
     for (i = 0; i < bgEventCount; i++)
diff --git a/src/fieldmap.c b/src/fieldmap.c
index c2362f6b9..e10f1af11 100644
--- a/src/fieldmap.c
+++ b/src/fieldmap.c
@@ -24,15 +24,15 @@ EWRAM_DATA u8 gGlobalFieldTintMode = QL_TINT_NONE;
 static const struct ConnectionFlags sDummyConnectionFlags = {};
 
 static void InitMapLayoutData(struct MapHeader *);
-static void InitBackupMapLayoutData(u16 *, u16, u16);
+static void InitBackupMapLayoutData(const u16 *, u16, u16);
 static void InitBackupMapLayoutConnections(struct MapHeader *);
 static void FillSouthConnection(struct MapHeader const *, struct MapHeader const *, s32);
 static void FillNorthConnection(struct MapHeader const *, struct MapHeader const *, s32);
 static void FillWestConnection(struct MapHeader const *, struct MapHeader const *, s32);
 static void FillEastConnection(struct MapHeader const *, struct MapHeader const *, s32);
 static void LoadSavedMapView(void);
-static struct MapConnection *GetIncomingConnection(u8, s32, s32);
-static bool8 IsPosInIncomingConnectingMap(u8, s32, s32, struct MapConnection *);
+static const struct MapConnection *GetIncomingConnection(u8, s32, s32);
+static bool8 IsPosInIncomingConnectingMap(u8, s32, s32, const struct MapConnection *);
 static bool8 IsCoordInIncomingConnectingMap(s32, s32, s32, s32);
 static u32 GetAttributeByMetatileIdAndMapLayout(const struct MapLayout *, u16, u8);
 
@@ -82,7 +82,7 @@ static const u8 sMetatileAttrShifts[METATILE_ATTRIBUTE_COUNT] = {
     [METATILE_ATTRIBUTE_7]              = 31
 };
 
-const struct MapHeader * GetMapHeaderFromConnection(struct MapConnection * connection)
+const struct MapHeader * GetMapHeaderFromConnection(const struct MapConnection * connection)
 {
     return Overworld_GetMapHeaderByGroupAndId(connection->mapGroup, connection->mapNum);
 }
@@ -112,7 +112,7 @@ static void InitMapLayoutData(struct MapHeader * mapHeader)
     InitBackupMapLayoutConnections(mapHeader);
 }
 
-static void InitBackupMapLayoutData(u16 *map, u16 width, u16 height)
+static void InitBackupMapLayoutData(const u16 *map, u16 width, u16 height)
 {
     s32 y;
     u16 *dest = VMap.map;
@@ -129,7 +129,7 @@ static void InitBackupMapLayoutData(u16 *map, u16 width, u16 height)
 static void InitBackupMapLayoutConnections(struct MapHeader *mapHeader)
 {
     s32 count;
-    struct MapConnection *connection;
+    const struct MapConnection *connection;
     s32 i;
 
     gMapConnectionFlags = sDummyConnectionFlags;
@@ -173,7 +173,7 @@ static void InitBackupMapLayoutConnections(struct MapHeader *mapHeader)
 static void FillConnection(s32 x, s32 y, const struct MapHeader *connectedMapHeader, s32 x2, s32 y2, s32 width, s32 height)
 {
     s32 i;
-    u16 *src;
+    const u16 *src;
     u16 *dest;
     s32 mapWidth;
 
@@ -628,7 +628,7 @@ bool32 CanCameraMoveInDirection(s32 direction)
     return TRUE;
 }
 
-static void SetPositionFromConnection(struct MapConnection *connection, int direction, s32 x, s32 y)
+static void SetPositionFromConnection(const struct MapConnection *connection, int direction, s32 x, s32 y)
 {
     struct MapHeader const *mapHeader;
     mapHeader = GetMapHeaderFromConnection(connection);
@@ -656,7 +656,7 @@ static void SetPositionFromConnection(struct MapConnection *connection, int dire
 bool8 CameraMove(s32 x, s32 y)
 {
     s32 direction;
-    struct MapConnection *connection;
+    const struct MapConnection *connection;
     s32 old_x, old_y;
     gCamera.active = FALSE;
     direction = GetPostCameraMoveMapBorderId(x, y);
@@ -683,10 +683,10 @@ bool8 CameraMove(s32 x, s32 y)
     return gCamera.active;
 }
 
-struct MapConnection *GetIncomingConnection(u8 direction, s32 x, s32 y)
+const struct MapConnection *GetIncomingConnection(u8 direction, s32 x, s32 y)
 {
     s32 count;
-    struct MapConnection *connection;
+    const struct MapConnection *connection;
     const struct MapConnections *connections = gMapHeader.connections;
     s32 i;
 
@@ -705,7 +705,7 @@ struct MapConnection *GetIncomingConnection(u8 direction, s32 x, s32 y)
 
 }
 
-static bool8 IsPosInIncomingConnectingMap(u8 direction, s32 x, s32 y, struct MapConnection *connection)
+static bool8 IsPosInIncomingConnectingMap(u8 direction, s32 x, s32 y, const struct MapConnection *connection)
 {
     struct MapHeader const *mapHeader;
     mapHeader = GetMapHeaderFromConnection(connection);
@@ -742,7 +742,7 @@ static bool32 IsCoordInConnectingMap(s32 coord, s32 max)
     return FALSE;
 }
 
-static s32 IsPosInConnectingMap(struct MapConnection *connection, s32 x, s32 y)
+static s32 IsPosInConnectingMap(const struct MapConnection *connection, s32 x, s32 y)
 {
     struct MapHeader const *mapHeader;
     mapHeader = GetMapHeaderFromConnection(connection);
@@ -758,10 +758,10 @@ static s32 IsPosInConnectingMap(struct MapConnection *connection, s32 x, s32 y)
     return FALSE;
 }
 
-struct MapConnection *GetMapConnectionAtPos(s16 x, s16 y)
+const struct MapConnection *GetMapConnectionAtPos(s16 x, s16 y)
 {
     s32 count;
-    struct MapConnection *connection;
+    const struct MapConnection *connection;
     s32 i;
     u8 direction;
     if (!gMapHeader.connections)
diff --git a/src/itemfinder.c b/src/itemfinder.c
index 7819b3944..deaa02661 100644
--- a/src/itemfinder.c
+++ b/src/itemfinder.c
@@ -287,7 +287,7 @@ static void SetNormalHiddenItem(u8 taskId)
 static bool8 HiddenItemAtPos(const struct MapEvents * events, s16 x, s16 y)
 {
     u8 bgEventCount = events->bgEventCount;
-    struct BgEvent * bgEvents = events->bgEvents;
+    const struct BgEvent * bgEvents = events->bgEvents;
     u16 eventFlag;
     int i;
 
@@ -309,7 +309,7 @@ static bool8 HiddenItemAtPos(const struct MapEvents * events, s16 x, s16 y)
     return FALSE;
 }
 
-static bool8 HiddenItemInConnectedMapAtPos(struct MapConnection * connection, s32 x, s32 y)
+static bool8 HiddenItemInConnectedMapAtPos(const struct MapConnection * connection, s32 x, s32 y)
 {
     const struct MapHeader * mapHeader;
     u16 localX, localY;
@@ -372,7 +372,7 @@ static void FindHiddenItemsInConnectedMaps(u8 taskId)
                 || var2 > curY
                 || curY >= height)
             {
-                struct MapConnection * conn = GetMapConnectionAtPos(curX, curY);
+                const struct MapConnection * conn = GetMapConnectionAtPos(curX, curY);
                 if (conn != NULL && HiddenItemInConnectedMapAtPos(conn, curX, curY) == TRUE)
                     RegisterHiddenItemRelativeCoordsIfCloser(taskId, curX - x, curY - y);
             }
diff --git a/src/teachy_tv.c b/src/teachy_tv.c
index 0f4e79099..0d4c31434 100644
--- a/src/teachy_tv.c
+++ b/src/teachy_tv.c
@@ -95,7 +95,7 @@ static u8 TeachyTvGrassAnimationCheckIfNeedsToGenerateGrassObj(s16 x, s16 y);
 static void TeachyTvGrassAnimationObjCallback(struct Sprite *sprite);
 static void TeachyTvRestorePlayerPartyCallback(void);
 static void TeachyTvPreBattleAnimAndSetBattleCallback(u8 taskId);
-static void TeachyTvLoadMapTilesetToBuffer(struct Tileset *ts, u8 *dstBuffer, u16 size);
+static void TeachyTvLoadMapTilesetToBuffer(const struct Tileset *ts, u8 *dstBuffer, u16 size);
 static void TeachyTvPushBackNewMapPalIndexArrayEntry(const struct MapLayout *mStruct, u16 *buf1, u8 *palIndexArray, u16 mapEntry, u16 offset);
 static void TeachyTvComputeMapTilesFromTilesetAndMetaTiles(const u16 *metaTilesArray, u8 *blockBuf, u8 *tileset);
 static void TeachyTvComputeSingleMapTileBlockFromTilesetAndMetaTiles(u8 *blockBuf, u8 *tileset, u8 metaTile);
@@ -1276,7 +1276,7 @@ static void TeachyTvLoadBg3Map(u16 *buffer)
     Free(blockIndicesBuffer);
 }
 
-static void TeachyTvLoadMapTilesetToBuffer(struct Tileset *ts, u8 *dstBuffer, u16 size)
+static void TeachyTvLoadMapTilesetToBuffer(const struct Tileset *ts, u8 *dstBuffer, u16 size)
 {
     if (ts)
     {