diff --git a/src/gfxinit.cpp b/src/gfxinit.cpp
index 46fbd3f7b7..d023f55546 100644
--- a/src/gfxinit.cpp
+++ b/src/gfxinit.cpp
@@ -43,10 +43,10 @@ static const SpriteID * const _landscape_spriteindexes[] = {
  * @param needs_palette_remap Whether the colours in the GRF file need a palette remap.
  * @return The number of loaded sprites.
  */
-static uint LoadGrfFile(const std::string &filename, uint load_index, bool needs_palette_remap)
+static uint LoadGrfFile(const std::string &filename, SpriteID load_index, bool needs_palette_remap)
 {
-	uint load_index_org = load_index;
-	uint sprite_id = 0;
+	SpriteID load_index_org = load_index;
+	SpriteID sprite_id = 0;
 
 	SpriteFile &file = OpenCachedSpriteFile(filename, BASESET_DIR, needs_palette_remap);
 
diff --git a/src/newgrf.cpp b/src/newgrf.cpp
index 7ffb998885..7795f20c73 100644
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -6469,7 +6469,7 @@ static void GraphicsNew(ByteReader &buf)
 
 	for (; num > 0; num--) {
 		_cur.nfo_line++;
-		int load_index = (replace == 0 ? _cur.spriteid++ : replace++);
+		SpriteID load_index = (replace == 0 ? _cur.spriteid++ : replace++);
 		LoadNextSprite(load_index, *_cur.file, _cur.nfo_line);
 		if (dup_oneway_sprites) {
 			DupSprite(load_index, load_index + SPR_ONEWAY_SLOPE_N_OFFSET);
@@ -7084,7 +7084,7 @@ static void SpriteReplace(ByteReader &buf)
 		}
 
 		for (uint j = 0; j < num_sprites; j++) {
-			int load_index = first_sprite + j;
+			SpriteID load_index = first_sprite + j;
 			_cur.nfo_line++;
 			LoadNextSprite(load_index, *_cur.file, _cur.nfo_line); // XXX
 
@@ -10014,7 +10014,7 @@ static void AfterLoadGRFs()
  * @param load_index The offset for the first sprite to add.
  * @param num_baseset Number of NewGRFs at the front of the list to look up in the baseset dir instead of the newgrf dir.
  */
-void LoadNewGRF(uint load_index, uint num_baseset)
+void LoadNewGRF(SpriteID load_index, uint num_baseset)
 {
 	/* In case of networking we need to "sync" the start values
 	 * so all NewGRFs are loaded equally. For this we use the
diff --git a/src/newgrf.h b/src/newgrf.h
index b08376dc57..5a4d661721 100644
--- a/src/newgrf.h
+++ b/src/newgrf.h
@@ -196,7 +196,7 @@ inline bool HasGrfMiscBit(GrfMiscBit bit)
 extern GRFLoadedFeatures _loaded_newgrf_features;
 
 void LoadNewGRFFile(struct GRFConfig *config, GrfLoadingStage stage, Subdirectory subdir, bool temporary);
-void LoadNewGRF(uint load_index, uint num_baseset);
+void LoadNewGRF(SpriteID load_index, uint num_baseset);
 void ReloadNewGRFData(); // in saveload/afterload.cpp
 void ResetNewGRFData();
 void ResetPersistentNewGRFData();
diff --git a/src/spritecache.cpp b/src/spritecache.cpp
index 9bcd98c1d0..35242178d5 100644
--- a/src/spritecache.cpp
+++ b/src/spritecache.cpp
@@ -573,7 +573,7 @@ void ReadGRFSpriteOffsets(SpriteFile &file)
 
 		/* Loop over all sprite section entries and store the file
 		 * offset for each newly encountered ID. */
-		uint32_t id, prev_id = 0;
+		SpriteID id, prev_id = 0;
 		while ((id = file.ReadDword()) != 0) {
 			if (id != prev_id) {
 				_grf_sprite_offsets[prev_id] = offset;
@@ -615,7 +615,7 @@ void ReadGRFSpriteOffsets(SpriteFile &file)
  * @param container_version Container version of the GRF.
  * @return True if a valid sprite was loaded, false on any error.
  */
-bool LoadNextSprite(int load_index, SpriteFile &file, uint file_sprite_id)
+bool LoadNextSprite(SpriteID load_index, SpriteFile &file, uint file_sprite_id)
 {
 	size_t file_pos = file.GetPos();
 
@@ -661,7 +661,7 @@ bool LoadNextSprite(int load_index, SpriteFile &file, uint file_sprite_id)
 
 	if (type == SpriteType::Invalid) return false;
 
-	if (static_cast<uint>(load_index) >= MAX_SPRITES) {
+	if (load_index >= MAX_SPRITES) {
 		UserError("Tried to load too many sprites (#{}; max {})", load_index, MAX_SPRITES);
 	}
 
diff --git a/src/spritecache.h b/src/spritecache.h
index 7aa01765d4..d6ba077a1e 100644
--- a/src/spritecache.h
+++ b/src/spritecache.h
@@ -77,7 +77,7 @@ std::span<const std::unique_ptr<SpriteFile>> GetCachedSpriteFiles();
 
 void ReadGRFSpriteOffsets(SpriteFile &file);
 size_t GetGRFSpriteOffset(uint32_t id);
-bool LoadNextSprite(int load_index, SpriteFile &file, uint file_sprite_id);
+bool LoadNextSprite(SpriteID load_index, SpriteFile &file, uint file_sprite_id);
 bool SkipSpriteData(SpriteFile &file, uint8_t type, uint16_t num);
 void DupSprite(SpriteID old_spr, SpriteID new_spr);
 
diff --git a/src/tests/mock_spritecache.cpp b/src/tests/mock_spritecache.cpp
index 38bb6804cd..222d49043f 100644
--- a/src/tests/mock_spritecache.cpp
+++ b/src/tests/mock_spritecache.cpp
@@ -15,7 +15,7 @@
 #include "../spritecache_internal.h"
 #include "../table/sprites.h"
 
-static bool MockLoadNextSprite(int load_index)
+static bool MockLoadNextSprite(SpriteID load_index)
 {
 	SimpleSpriteAllocator allocator;
 	static Sprite *sprite = allocator.Allocate<Sprite>(sizeof(*sprite));
@@ -33,7 +33,7 @@ static bool MockLoadNextSprite(int load_index)
 	sc->control_flags = 0;
 
 	/* Fill with empty sprites up until the default sprite count. */
-	return (uint)load_index < SPR_OPENTTD_BASE + OPENTTD_SPRITE_COUNT;
+	return load_index < SPR_OPENTTD_BASE + OPENTTD_SPRITE_COUNT;
 }
 
 void MockGfxLoadSprites()
@@ -43,7 +43,7 @@ void MockGfxLoadSprites()
 
 	GfxInitSpriteMem();
 
-	int load_index = 0;
+	SpriteID load_index = 0;
 	while (MockLoadNextSprite(load_index)) {
 		load_index++;
 	}