diff --git a/src/fios.h b/src/fios.h
--- a/src/fios.h
+++ b/src/fios.h
@@ -23,6 +23,12 @@ enum SaveLoadInvalidateWindowData {
 	SLIWD_FILTER_CHANGES,        ///< The filename filter has changed (via the editbox)
 };
 
+enum PatchpackSaveExtensionType {
+	PSXT_NONE,
+	PSXT_MODIFIED,
+	PSXT_EXTENDED
+};
+
 typedef SmallMap<uint, CompanyProperties *> CompanyPropertiesMap;
 
 /**
@@ -45,6 +51,9 @@ struct LoadCheckData {
 
 	struct LoggedAction *gamelog_action;          ///< Gamelog actions
 	uint gamelog_actions;                         ///< Number of gamelog actions
+	uint16 save_version;                          ///< Save version
+	PatchpackSaveExtensionType save_ext_type;     ///< Extension type
+	std::string save_version_label;               ///< Save version label
 
 	LoadCheckData() : error_data(nullptr), grfconfig(nullptr),
 			grf_compatibility(GLC_NOT_FOUND), gamelog_action(nullptr), gamelog_actions(0)