diff --git a/wow_sync/tray/tray_macos.py b/wow_sync/tray/tray_macos.py
index 5462379..ad84c5d 100644
--- a/wow_sync/tray/tray_macos.py
+++ b/wow_sync/tray/tray_macos.py
@@ -2,8 +2,7 @@
 macOS native implementation using PyObjC.
 
 Uses PyObjC to directly access macOS NSStatusBar APIs for native
-status bar icon integration. This integrates with the main thread
-using performSelectorOnMainThread to avoid threading issues.
+status bar icon integration.
 """
 
 from typing import Optional, Callable
@@ -200,32 +199,24 @@ async def setup(self):
             str(icon_path), callbacks
         )
         
-        # Setup status bar on main thread
-        # performSelectorOnMainThread doesn't return the selector's result,
-        # so we call it and then check if status_item was created
-        self.controller.performSelectorOnMainThread_withObject_waitUntilDone_(
-            objc.selector(self.controller.setupStatusBar, signature=b'B@:'),
-            None,
-            True  # Wait until done
-        )
+        # Setup status bar directly
+        # This is called from async_mainloop which runs on the main thread,
+        # satisfying AppKit's requirement for UI operations on the main thread.
+        # Callbacks are already wrapped with root.after() for thread safety.
+        success = self.controller.setupStatusBar()
         
-        # Check if setup was successful by verifying status_item exists
-        if not self.controller.status_item:
+        if not success:
             raise RuntimeError("Failed to setup status bar")
         
-        # Longer delay to ensure the menu is fully initialized
-        await asyncio.sleep(0.3)
+        # Small delay to ensure the menu is fully initialized
+        await asyncio.sleep(0.1)
     
     def update_monitor_menu(self, is_enabled: bool):
         """Update the auto-sync menu item label."""
         if self.controller and self.controller.monitor_menu_item:
             label = "Disable Auto-Sync" if is_enabled else "Enable Auto-Sync"
-            # Update on main thread
-            self.controller.performSelectorOnMainThread_withObject_waitUntilDone_(
-                objc.selector(self.controller.updateMonitorMenuTitle_, signature=b'v@:@'),
-                label,
-                False  # Don't wait - async update is fine
-            )
+            # Update directly - called from MainWindow which is on the main thread
+            self.controller.updateMonitorMenuTitle_(label)
     
     def cleanup(self):
         """Cleanup tray icon."""
diff --git a/wow_sync/ui/main_window.py b/wow_sync/ui/main_window.py
index f15ea56..3e4b576 100644
--- a/wow_sync/ui/main_window.py
+++ b/wow_sync/ui/main_window.py
@@ -159,12 +159,15 @@ def _create_widgets(self):
     async def _setup_tray(self):
         """Setup system tray icon with automatic fallback between implementations."""
         try:
+            # Wrap callbacks with root.after() to ensure they run on the main Tkinter thread
+            # This is necessary because tray implementations (especially Windows) may invoke
+            # callbacks from different threads, and Tkinter is not thread-safe
             self.tray_icon = TrayIcon(
-                on_show=self._show_window,
-                on_quit=self.quit_app,
-                on_pull=self._pull_from_remote,
-                on_push=self._push_to_remote,
-                on_toggle_monitor=self._tray_toggle_monitor
+                on_show=lambda: self.root.after(0, self._show_window),
+                on_quit=lambda: self.root.after(0, self.quit_app),
+                on_pull=lambda: self.root.after(0, self._pull_from_remote),
+                on_push=lambda: self.root.after(0, self._push_to_remote),
+                on_toggle_monitor=lambda: self.root.after(0, self._tray_toggle_monitor)
             )
             success, message = await self.tray_icon.setup()