diff --git a/src/openttd.cpp b/src/openttd.cpp
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -1393,7 +1393,7 @@ void StateGameLoop()
  */
 static void DoAutosave()
 {
-	static int _autosave_ctr = 0;
+	static FiosNumberedSaveName _autosave_ctr("autosave");
 	DoAutoOrNetsave(_autosave_ctr);
 }