diff --git a/customtkinter/windows/ctk_input_dialog.py b/customtkinter/windows/ctk_input_dialog.py
index 0e3d198..d0c204f 100644
--- a/customtkinter/windows/ctk_input_dialog.py
+++ b/customtkinter/windows/ctk_input_dialog.py
@@ -42,6 +42,8 @@ class CTkInputDialog:
         self.top.focus_force()
         self.top.grab_set()
 
+        self.top.protocol("WM_DELETE_WINDOW", self.on_closing)
+
         self.top.after(10, self.create_widgets)  # create widgets with slight delay, to avoid white flickering of background
 
     def create_widgets(self):
@@ -95,6 +97,9 @@ class CTkInputDialog:
         self.user_input = self.entry.get()
         self.running = False
 
+    def on_closing(self):
+        self.running = False
+
     def cancel_event(self):
         self.running = False