diff --git a/dislocker_client_shutdown.py b/dislocker_client_shutdown.py
index 7411b3b..eb67e06 100644
--- a/dislocker_client_shutdown.py
+++ b/dislocker_client_shutdown.py
@@ -58,7 +58,7 @@ class App(tkinter.Tk):
         self.title(f"{app_name} | てすと")
         self.iconbitmap(default=resource_path + '\\icon\\dislocker.ico')
 
-        self.protocol("WM_DELETE_WINDOW", self.handler_close)
+        self.protocol("WM_SAVE_YOURSELF", self.handler_close)
 
         self.frame = tkinter.Frame(self)
         self.frame.grid(row=0, column=0, sticky='nsew')