diff --git a/src/game.c b/src/game.c
index dd11008..43ff2d0 100644
--- a/src/game.c
+++ b/src/game.c
@@ -128,7 +128,10 @@ game_loop ()
     draw_field ();
     if (GT_MP_PTP)
         net_game_fillsockaddr ();
-
+	if (strcmp(VERSION,"0.9.9") ) {
+		menu_displaytext ("Error", " Unauthorized version change ", 64, 0, 0);
+		return;
+	}
     SDL_Flip (gfx.screen);
 
     timestamp = SDL_GetTicks (); // needed for time sync.