diff --git a/src/conio/sdl_con.c b/src/conio/sdl_con.c
index 8aab2eff88d96826f0b848c8866abffabe7e199e..3eda109c001be8c6c3e21fa2aa67aa5f383fcd89 100644
--- a/src/conio/sdl_con.c
+++ b/src/conio/sdl_con.c
@@ -1421,6 +1421,7 @@ static int sdl_mouse_thread(void *data)
 		if(mouse_wait())
 			sdl_add_key(CIO_KEY_MOUSE);
 	}
+	return 0;
 }
 
 static int win_to_text_xpos(int winpos)