diff --git a/src/core/toga/app.py b/src/core/toga/app.py
index 419cf36176..4b242ac9cf 100644
--- a/src/core/toga/app.py
+++ b/src/core/toga/app.py
@@ -500,6 +500,8 @@ def main_loop(self):
     def exit(self):
         """ Quit the application gracefully.
         """
+        if self.on_exit is not None:
+            self.on_exit(self)
         self._impl.exit()
 
     @property