diff --git a/ai.c b/ai.c
index 18bdc162fa..f740cb28da 100644
--- a/ai.c
+++ b/ai.c
@@ -3640,7 +3640,7 @@ static void AiStateRemoveStation(Player *p)
 
 }
 
-static void AiRemovePlayerRailOrRoad(Player *p, uint tile)
+static void AiRemovePlayerRailOrRoad(Player *p, TileIndex tile)
 {
 	byte m5;
 
@@ -3758,10 +3758,11 @@ pos_3:
 
 static void AiStateRemoveTrack(Player *p)
 {
-	int num = 1000;
+	/* Was 1000 for standard 8x8 maps. */
+	int num = MapSizeX() * 4;
 
 	do {
-		uint tile = ++p->ai.state_counter;
+		TileIndex tile = ++p->ai.state_counter;
 
 		// Iterated all tiles?
 		if (tile >= MapSize()) {
diff --git a/player.h b/player.h
index 2c93c2b0ee..2fc8fd89b0 100644
--- a/player.h
+++ b/player.h
@@ -27,7 +27,7 @@ typedef struct AiBuildRec {
 typedef struct PlayerAI {
 	byte state;
 	byte tick; // Used to determine how often to move
-	uint16 state_counter;
+	uint32 state_counter; // Can hold tile index!
 	uint16 timeout_counter;
 
 	byte state_mode;
diff --git a/players.c b/players.c
index 64c6c52526..eb5733494c 100644
--- a/players.c
+++ b/players.c
@@ -974,7 +974,8 @@ static const byte _player_economy_desc[] = {
 static const byte _player_ai_desc[] = {
 	SLE_VAR(PlayerAI,state,							SLE_UINT8),
 	SLE_VAR(PlayerAI,tick,							SLE_UINT8),
-	SLE_VAR(PlayerAI,state_counter,			SLE_UINT16),
+	SLE_CONDVAR(PlayerAI,state_counter, SLE_FILE_U16 | SLE_VAR_U32, 0, 12),
+	SLE_CONDVAR(PlayerAI,state_counter, SLE_UINT32, 13, 255),
 	SLE_VAR(PlayerAI,timeout_counter,		SLE_UINT16),
 
 	SLE_VAR(PlayerAI,state_mode,				SLE_UINT8),
diff --git a/saveload.c b/saveload.c
index d436e97f37..e9e504a5c2 100644
--- a/saveload.c
+++ b/saveload.c
@@ -8,7 +8,7 @@
 #include "saveload.h"
 
 enum {
-	SAVEGAME_MAJOR_VERSION = 0xC,
+	SAVEGAME_MAJOR_VERSION = 13,
 	SAVEGAME_MINOR_VERSION = 0x1,
 
 	SAVEGAME_LOADABLE_VERSION = (SAVEGAME_MAJOR_VERSION << 8) + SAVEGAME_MINOR_VERSION