diff --git a/qt/aqt/__init__.py b/qt/aqt/__init__.py
index 3b8872448..02b70af1f 100644
--- a/qt/aqt/__init__.py
+++ b/qt/aqt/__init__.py
@@ -285,6 +285,22 @@ def setupLangAndBackend(
 ##########################################################################
 
 
+class NativeEventFilter(QAbstractNativeEventFilter):
+    def nativeEventFilter(
+        self, eventType: Any, message: Any
+    ) -> tuple[bool, Optional[sip.voidptr]]:
+        if eventType == "windows_generic_MSG":
+            import ctypes
+
+            msg = ctypes.wintypes.MSG.from_address(int(message))
+            if msg.message == 17:  # WM_QUERYENDSESSION
+                if mw.can_auto_sync():
+                    mw.app._set_windows_shutdown_block_reason(tr.sync_syncing())
+                    mw.progress.single_shot(100, mw.unloadProfileAndExit)
+                    return (True, 0)
+        return (False, 0)
+
+
 class AnkiApp(QApplication):
     # Single instance support on Win32/Linux
     ##################################################
@@ -298,6 +314,27 @@ class AnkiApp(QApplication):
         QApplication.__init__(self, argv)
         self.installEventFilter(self)
         self._argv = argv
+        self._native_event_filter = NativeEventFilter()
+        if is_win:
+            self.installNativeEventFilter(self._native_event_filter)
+
+    def _set_windows_shutdown_block_reason(self, reason: str) -> None:
+        if is_win:
+            import ctypes
+            from ctypes import windll, wintypes  # type: ignore
+
+            windll.user32.ShutdownBlockReasonCreate(
+                wintypes.HWND.from_param(int(mw.effectiveWinId())),
+                ctypes.c_wchar_p(reason),
+            )
+
+    def _unset_windows_shutdown_block_reason(self) -> None:
+        if is_win:
+            from ctypes import windll, wintypes  # type: ignore
+
+            windll.user32.ShutdownBlockReasonDestroy(
+                wintypes.HWND.from_param(int(mw.effectiveWinId())),
+            )
 
     def secondInstance(self) -> bool:
         # we accept only one command line argument. if it's missing, send
diff --git a/qt/aqt/main.py b/qt/aqt/main.py
index 08f74d447..61f2363fc 100644
--- a/qt/aqt/main.py
+++ b/qt/aqt/main.py
@@ -573,6 +573,7 @@ class AnkiQt(QMainWindow):
         self.backend.await_backup_completion()
         self.deleteLater()
         app = self.app
+        app._unset_windows_shutdown_block_reason()
 
         def exit():
             # try to ensure Qt objects are deleted in a logical order,