diff --git a/src/fios.h b/src/fios.h
--- a/src/fios.h
+++ b/src/fios.h
@@ -164,6 +164,7 @@ const char *FiosBrowseTo(const FiosItem 
 
 StringID FiosGetDescText(const char **path, uint64 *total_free);
 bool FiosDelete(const char *name);
+void FiosMakeHeightmapName(char *buf,const char *name, size_t size);
 void FiosMakeSavegameName(char *buf, const char *name, size_t size);
 
 FiosType FiosGetSavegameListCallback(SaveLoadDialogMode mode, const char *file, const char *ext, char *title, const char *last);