diff --git a/ui/ozone/platform/x11/x11_window.cc b/ui/ozone/platform/x11/x11_window.cc
index 1366525c41b8d..e116be3274af8 100644
--- a/ui/ozone/platform/x11/x11_window.cc
+++ b/ui/ozone/platform/x11/x11_window.cc
@@ -1424,7 +1424,14 @@ uint32_t X11Window::DispatchEvent(const PlatformEvent& event) {
   auto& current_xevent = *connection_->dispatching_event();
 
   if (event->IsMouseEvent()) {
+    // MouseOnWindow() -> OnCursorUpdate() can re-enter GetBoundsInPixels() via
+    // the Screen lookup and synchronously destroy `this` (see the warning at
+    // GetBoundsInPixels()).
+    auto weak_this = weak_ptr_factory_.GetWeakPtr();
     X11WindowManager::GetInstance()->MouseOnWindow(this);
+    if (!weak_this) {
+      return POST_DISPATCH_STOP_PROPAGATION;
+    }
   }
 #if BUILDFLAG(USE_ATK)
   if (HandleAsAtkEvent(current_xevent)) {