diff --git a/src/fileio.cpp b/src/fileio.cpp
index a8cf964a03..ad278e15fe 100644
--- a/src/fileio.cpp
+++ b/src/fileio.cpp
@@ -74,18 +74,18 @@ static void FioRestoreFile(int slot)
 #endif /* LIMITED_FDS */
 
 /* Seek to a file and a position */
-void FioSeekToFile(uint32 pos)
+void FioSeekToFile(uint8 slot, uint32 pos)
 {
 	FILE *f;
 #if defined(LIMITED_FDS)
 	/* Make sure we have this file open */
-	FioRestoreFile(pos >> 24);
+	FioRestoreFile(slot);
 #endif /* LIMITED_FDS */
-	f = _fio.handles[pos >> 24];
+	f = _fio.handles[slot];
 	assert(f != NULL);
 	_fio.cur_fh = f;
-	_fio.filename = _fio.filenames[pos >> 24];
-	FioSeekTo(GB(pos, 0, 24), SEEK_SET);
+	_fio.filename = _fio.filenames[slot];
+	FioSeekTo(pos, SEEK_SET);
 }
 
 byte FioReadByte()
@@ -180,6 +180,7 @@ void FioOpenFile(int slot, const char *filename)
 #endif /* LIMITED_FDS */
 	f = FioFOpenFile(filename);
 	if (f == NULL) error("Cannot open file '%s'", filename);
+	uint32 pos = ftell(f);
 
 	FioCloseFile(slot); // if file was opened before, close it
 	_fio.handles[slot] = f;
@@ -188,7 +189,7 @@ void FioOpenFile(int slot, const char *filename)
 	_fio.usage_count[slot] = 0;
 	_fio.open_handles++;
 #endif /* LIMITED_FDS */
-	FioSeekToFile(slot << 24);
+	FioSeekToFile(slot, pos);
 }
 
 const char *_subdirs[NUM_SUBDIRS] = {
diff --git a/src/fileio.h b/src/fileio.h
index 8596dc1231..a12c01e653 100644
--- a/src/fileio.h
+++ b/src/fileio.h
@@ -8,7 +8,7 @@
 #include "helpers.hpp"
 
 void FioSeekTo(uint32 pos, int mode);
-void FioSeekToFile(uint32 pos);
+void FioSeekToFile(uint8 slot, uint32 pos);
 uint32 FioGetPos();
 const char *FioGetFilename();
 byte FioReadByte();
diff --git a/src/newgrf.cpp b/src/newgrf.cpp
index bb7dbe3acd..25066d2f3e 100644
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -4506,9 +4506,9 @@ static void LoadGRFSound(byte *buf, int len)
 				break;
 
 			case 'atad': // 'data'
-				se->file_size    = size;
-				se->file_offset  = FioGetPos() - (len - (buf - buf_start)) + 1;
-				se->file_offset |= _file_index << 24;
+				se->file_size   = size;
+				se->file_offset = FioGetPos() - (len - (buf - buf_start)) + 1;
+				se->file_slot   = _file_index;
 
 				/* Set default volume and priority */
 				se->volume = 0x80;
diff --git a/src/sound.cpp b/src/sound.cpp
index 249ff73e30..a63e9564fc 100644
--- a/src/sound.cpp
+++ b/src/sound.cpp
@@ -45,6 +45,7 @@ static void OpenBankFile(const char *filename)
 	FioSeekTo(0, SEEK_SET);
 
 	for (i = 0; i != count; i++) {
+		fe[i].file_slot = SOUND_SLOT;
 		fe[i].file_offset = FioReadDword();
 		fe[i].file_size = FioReadDword();
 	}
@@ -75,7 +76,8 @@ static void OpenBankFile(const char *filename)
 					FioSeekTo(size - (2 + 2 + 4 + 4 + 2 + 1), SEEK_CUR);
 				} else if (tag == 'atad') {
 					fe->file_size = size;
-					fe->file_offset = FioGetPos() | (SOUND_SLOT << 24);
+					fe->file_slot = SOUND_SLOT;
+					fe->file_offset = FioGetPos();
 					break;
 				} else {
 					fe->file_size = 0;
@@ -91,7 +93,8 @@ static void OpenBankFile(const char *filename)
 			fe->channels = 1;
 			fe->rate = 11025;
 			fe->bits_per_sample = 8;
-			fe->file_offset = FioGetPos() | (SOUND_SLOT << 24);
+			fe->file_slot = SOUND_SLOT;
+			fe->file_offset = FioGetPos();
 		}
 	}
 }
@@ -114,7 +117,7 @@ static bool SetBankSource(MixerChannel *mc, uint bank)
 	int8 *mem = MallocT<int8>(fe->file_size);
 	if (mem == NULL) return false;
 
-	FioSeekToFile(fe->file_offset);
+	FioSeekToFile(fe->file_slot, fe->file_offset);
 	FioReadBlock(mem, fe->file_size);
 
 	for (i = 0; i != fe->file_size; i++)
diff --git a/src/sound.h b/src/sound.h
index ff5c130d97..2b3355a9ef 100644
--- a/src/sound.h
+++ b/src/sound.h
@@ -21,6 +21,7 @@ struct MusicFileSettings {
 VARDEF MusicFileSettings msf;
 
 struct FileEntry {
+	uint8 file_slot;
 	uint32 file_offset;
 	uint32 file_size;
 	uint16 rate;
diff --git a/src/spritecache.cpp b/src/spritecache.cpp
index 710bca443d..fb8e684d36 100644
--- a/src/spritecache.cpp
+++ b/src/spritecache.cpp
@@ -25,6 +25,7 @@ uint _sprite_cache_size = 4;
 
 struct SpriteCache {
 	void *ptr;
+	uint8 file_slot;
 	uint32 file_pos;
 	int16 lru;
 	uint32 id;
@@ -127,6 +128,7 @@ void* AllocSprite(size_t);
 
 static void* ReadSprite(SpriteCache *sc, SpriteID id, bool real_sprite)
 {
+	uint8 file_slot = sc->file_slot;
 	uint32 file_pos = sc->file_pos;
 
 	DEBUG(sprite, 9, "Load sprite %d", id);
@@ -136,7 +138,8 @@ static void* ReadSprite(SpriteCache *sc, SpriteID id, bool real_sprite)
 
 		/* SPR_IMG_QUERY is a BIG FAT RED ? */
 		id = SPR_IMG_QUERY;
-		file_pos = GetSpriteCache(SPR_IMG_QUERY)->file_pos;
+		file_slot = GetSpriteCache(SPR_IMG_QUERY)->file_slot;
+		file_pos  = GetSpriteCache(SPR_IMG_QUERY)->file_pos;
 	}
 
 	if (BlitterFactoryBase::GetCurrentBlitter()->GetScreenDepth() == 32) {
@@ -145,7 +148,7 @@ static void* ReadSprite(SpriteCache *sc, SpriteID id, bool real_sprite)
 		SpriteLoaderPNG sprite_loader;
 		SpriteLoader::Sprite sprite;
 
-		if (sprite_loader.LoadSprite(&sprite, sc->grf_name, sc->id)) {
+		if (sprite_loader.LoadSprite(&sprite, sc->grf_name, 0, sc->id)) {
 			sc->ptr = BlitterFactoryBase::GetCurrentBlitter()->Encode(&sprite, &AllocSprite);
 			free(sprite.data);
 
@@ -161,7 +164,7 @@ static void* ReadSprite(SpriteCache *sc, SpriteID id, bool real_sprite)
 #endif /* WITH_PNG */
 	}
 
-	FioSeekToFile(file_pos);
+	FioSeekToFile(file_slot, file_pos);
 
 	/* Read the size and type */
 	int num  = FioReadWord();
@@ -232,7 +235,7 @@ static void* ReadSprite(SpriteCache *sc, SpriteID id, bool real_sprite)
 	SpriteLoaderGrf sprite_loader;
 	SpriteLoader::Sprite sprite;
 
-	if (!sprite_loader.LoadSprite(&sprite, sc->grf_name, file_pos)) return NULL;
+	if (!sprite_loader.LoadSprite(&sprite, sc->grf_name, file_slot, file_pos)) return NULL;
 	if (id == 142) sprite.height = 10; // Compensate for a TTD bug
 	sc->ptr = BlitterFactoryBase::GetCurrentBlitter()->Encode(&sprite, &AllocSprite);
 	free(sprite.data);
@@ -241,10 +244,10 @@ static void* ReadSprite(SpriteCache *sc, SpriteID id, bool real_sprite)
 }
 
 
-bool LoadNextSprite(int load_index, byte file_index, uint file_sprite_id)
+bool LoadNextSprite(int load_index, byte file_slot, uint file_sprite_id)
 {
 	SpriteCache *sc;
-	uint32 file_pos = FioGetPos() | (file_index << 24);
+	uint32 file_pos = FioGetPos();
 
 	if (!ReadSpriteHeaderSkipData()) return false;
 
@@ -253,6 +256,7 @@ bool LoadNextSprite(int load_index, byte file_index, uint file_sprite_id)
 	}
 
 	sc = AllocateSpriteCache(load_index);
+	sc->file_slot = file_slot;
 	sc->file_pos = file_pos;
 	sc->ptr = NULL;
 	sc->lru = 0;
@@ -280,6 +284,7 @@ void DupSprite(SpriteID old_spr, SpriteID new_spr)
 	SpriteCache *scold = GetSpriteCache(old_spr);
 	SpriteCache *scnew = AllocateSpriteCache(new_spr);
 
+	scnew->file_slot = scold->file_slot;
 	scnew->file_pos = scold->file_pos;
 	scnew->ptr = NULL;
 	scnew->id = scold->id;
diff --git a/src/spriteloader/grf.cpp b/src/spriteloader/grf.cpp
index 79095e4db7..e41732b505 100644
--- a/src/spriteloader/grf.cpp
+++ b/src/spriteloader/grf.cpp
@@ -8,10 +8,10 @@
 #include "../debug.h"
 #include "grf.hpp"
 
-bool SpriteLoaderGrf::LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint32 file_pos)
+bool SpriteLoaderGrf::LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint8 file_slot, uint32 file_pos)
 {
 	/* Open the right file and go to the correct position */
-	FioSeekToFile(file_pos);
+	FioSeekToFile(file_slot, file_pos);
 
 	/* Read the size and type */
 	int num = FioReadWord();
diff --git a/src/spriteloader/grf.hpp b/src/spriteloader/grf.hpp
index e6e67be156..fe94053392 100644
--- a/src/spriteloader/grf.hpp
+++ b/src/spriteloader/grf.hpp
@@ -12,7 +12,7 @@ public:
 	/**
 	 * Load a sprite from the disk and return a sprite struct which is the same for all loaders.
 	 */
-	bool LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint32 file_pos);
+	bool LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint8 file_slot, uint32 file_pos);
 };
 
 #endif /* SPRITELOADER_GRF_HPP */
diff --git a/src/spriteloader/png.cpp b/src/spriteloader/png.cpp
index 6048c6fdd7..2bb7227d5e 100644
--- a/src/spriteloader/png.cpp
+++ b/src/spriteloader/png.cpp
@@ -180,7 +180,7 @@ static bool LoadPNG(SpriteLoader::Sprite *sprite, const char *filename, uint32 i
 	return true;
 }
 
-bool SpriteLoaderPNG::LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint32 file_pos)
+bool SpriteLoaderPNG::LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint8 file_slot, uint32 file_pos)
 {
 	if (!LoadPNG(sprite, filename, file_pos, false)) return false;
 	if (!LoadPNG(sprite, filename, file_pos, true)) return false;
diff --git a/src/spriteloader/png.hpp b/src/spriteloader/png.hpp
index 7375012684..eb3719180e 100644
--- a/src/spriteloader/png.hpp
+++ b/src/spriteloader/png.hpp
@@ -12,7 +12,7 @@ public:
 	/**
 	 * Load a sprite from the disk and return a sprite struct which is the same for all loaders.
 	 */
-	bool LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint32 file_pos);
+	bool LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint8 file_slot, uint32 file_pos);
 };
 
 #endif /* SPRITELOADER_PNG_HPP */
diff --git a/src/spriteloader/spriteloader.hpp b/src/spriteloader/spriteloader.hpp
index fe0e6ab8e0..47d1b7d405 100644
--- a/src/spriteloader/spriteloader.hpp
+++ b/src/spriteloader/spriteloader.hpp
@@ -26,7 +26,7 @@ public:
 	/**
 	 * Load a sprite from the disk and return a sprite struct which is the same for all loaders.
 	 */
-	virtual bool LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint32 file_pos) = 0;
+	virtual bool LoadSprite(SpriteLoader::Sprite *sprite, const char *filename, uint8 file_slot, uint32 file_pos) = 0;
 
 	virtual ~SpriteLoader() { }
 };