diff --git a/src/plugins/platforms/ios/qiosviewcontroller.mm b/src/plugins/platforms/ios/qiosviewcontroller.mm
index c4e8968232..6f157353df 100644
--- a/src/plugins/platforms/ios/qiosviewcontroller.mm
+++ b/src/plugins/platforms/ios/qiosviewcontroller.mm
@@ -107,8 +107,11 @@
 {
     Q_UNUSED(subview);
 
-    Q_ASSERT(self.window);
     UIWindow *uiWindow = self.window;
+    // uiWindow can be null when closing from the ios "app manager" and the app is
+    // showing a native window like UIDocumentBrowserViewController
+    if (!uiWindow)
+        return;
 
     if (uiWindow.screen != [UIScreen mainScreen] && self.subviews.count == 1) {
         // We're about to remove the last view of an external screen, so go back