diff --git a/Sources/ContentView.swift b/Sources/ContentView.swift
index fcaa679276c0..fc2ca2a35c68 100644
--- a/Sources/ContentView.swift
+++ b/Sources/ContentView.swift
@@ -1858,6 +1858,26 @@ func installFileDropOverlay(on window: NSWindow, tabManager: TabManager) -> Bool
     return true
 }
 
+private func installFileDropOverlayWhenReady(
+    on window: NSWindow,
+    tabManager: TabManager,
+    remainingAttempts: Int = 16
+) {
+    guard !installFileDropOverlay(on: window, tabManager: tabManager),
+          remainingAttempts > 0 else { return }
+
+    // Defer retrying until the next main-loop turn so we don't mutate the
+    // NSThemeFrame hierarchy while SwiftUI/AppKit is still attaching views.
+    DispatchQueue.main.async { [weak window, weak tabManager] in
+        guard let window, let tabManager else { return }
+        installFileDropOverlayWhenReady(
+            on: window,
+            tabManager: tabManager,
+            remainingAttempts: remainingAttempts - 1
+        )
+    }
+}
+
 struct ContentView: View {
     @ObservedObject var updateViewModel: UpdateViewModel
     let windowId: UUID
@@ -3796,12 +3816,7 @@ struct ContentView: View {
                 sidebarState: sidebarState,
                 sidebarSelectionState: sidebarSelectionState
             )
-        }))
-
-        // Install the file-drop overlay once the window hierarchy is ready, outside the
-        // high-frequency body-level window styling accessor above.
-        view = AnyView(view.background(WindowSetupAccessor { window in
-            installFileDropOverlay(on: window, tabManager: tabManager)
+            installFileDropOverlayWhenReady(on: window, tabManager: tabManager)
         }))
 
         return view
diff --git a/Sources/WindowAccessor.swift b/Sources/WindowAccessor.swift
index ecf32b0f76d2..a3d257a37fc5 100644
--- a/Sources/WindowAccessor.swift
+++ b/Sources/WindowAccessor.swift
@@ -36,48 +36,6 @@ struct WindowAccessor: NSViewRepresentable {
     }
 }
 
-/// Replays the window callback until setup succeeds, then dedupes future updates for that window.
-struct WindowSetupAccessor: NSViewRepresentable {
-    let onWindow: (NSWindow) -> Bool
-
-    init(onWindow: @escaping (NSWindow) -> Bool) {
-        self.onWindow = onWindow
-    }
-
-    func makeCoordinator() -> Coordinator {
-        Coordinator()
-    }
-
-    func makeNSView(context: Context) -> WindowObservingView {
-        let view = WindowObservingView()
-        view.onWindow = { window in
-            guard context.coordinator.completedWindow !== window else { return }
-            if onWindow(window) {
-                context.coordinator.completedWindow = window
-            }
-        }
-        return view
-    }
-
-    func updateNSView(_ nsView: WindowObservingView, context: Context) {
-        nsView.onWindow = { window in
-            guard context.coordinator.completedWindow !== window else { return }
-            if onWindow(window) {
-                context.coordinator.completedWindow = window
-            }
-        }
-        if let window = nsView.window {
-            nsView.onWindow?(window)
-        }
-    }
-}
-
-extension WindowSetupAccessor {
-    final class Coordinator {
-        weak var completedWindow: NSWindow?
-    }
-}
-
 extension WindowAccessor {
     final class Coordinator {
         weak var lastWindow: NSWindow?