diff --git a/Servers/WindowServer/WSClientConnection.cpp b/Servers/WindowServer/WSClientConnection.cpp
index 0b02575837..393a5de426 100644
--- a/Servers/WindowServer/WSClientConnection.cpp
+++ b/Servers/WindowServer/WSClientConnection.cpp
@@ -77,6 +77,8 @@ WSClientConnection::~WSClientConnection()
 {
     WSMenuManager::the().close_all_menus_from_client({}, *this);
     auto windows = move(m_windows);
+    for (auto& window : windows)
+        window.value->detach_client({});
 }
 
 void WSClientConnection::die()
diff --git a/Servers/WindowServer/WSWindow.cpp b/Servers/WindowServer/WSWindow.cpp
index f3d168b056..a9980b9d94 100644
--- a/Servers/WindowServer/WSWindow.cpp
+++ b/Servers/WindowServer/WSWindow.cpp
@@ -63,6 +63,7 @@ WSWindow::WSWindow(WSClientConnection& client, WSWindowType window_type, int win
     , m_resizable(resizable)
     , m_fullscreen(fullscreen)
     , m_window_id(window_id)
+    , m_client_id(client.client_id())
     , m_icon(default_window_icon())
     , m_frame(*this)
 {
@@ -76,6 +77,10 @@ WSWindow::WSWindow(WSClientConnection& client, WSWindowType window_type, int win
 
 WSWindow::~WSWindow()
 {
+    // Detach from client at the start of teardown since we don't want
+    // to confuse things by trying to send messages to it.
+    m_client = nullptr;
+
     WSWindowManager::the().remove_window(*this);
 }
 
diff --git a/Servers/WindowServer/WSWindow.h b/Servers/WindowServer/WSWindow.h
index 91ab87e210..f77bd3ad30 100644
--- a/Servers/WindowServer/WSWindow.h
+++ b/Servers/WindowServer/WSWindow.h
@@ -114,6 +114,9 @@ public:
     WSWindowType type() const { return m_type; }
     int window_id() const { return m_window_id; }
 
+    bool is_internal() const { return m_client_id == -1; }
+    i32 client_id() const { return m_client_id; }
+
     String title() const { return m_title; }
     void set_title(const String&);
 
@@ -219,6 +222,8 @@ public:
     WSWindow* m_next { nullptr };
     WSWindow* m_prev { nullptr };
 
+    void detach_client(Badge<WSClientConnection>) { m_client = nullptr; }
+
 private:
     void handle_mouse_event(const WSMouseEvent&);
     void update_menu_item_text(PopupMenuItem item);
@@ -248,6 +253,7 @@ private:
     RefPtr<GraphicsBitmap> m_backing_store;
     RefPtr<GraphicsBitmap> m_last_backing_store;
     int m_window_id { -1 };
+    i32 m_client_id { -1 };
     float m_opacity { 1 };
     Size m_size_increment;
     Size m_base_size;
diff --git a/Servers/WindowServer/WSWindowManager.cpp b/Servers/WindowServer/WSWindowManager.cpp
index 67cc532314..2c1290a141 100644
--- a/Servers/WindowServer/WSWindowManager.cpp
+++ b/Servers/WindowServer/WSWindowManager.cpp
@@ -205,13 +205,14 @@ void WSWindowManager::remove_window(WSWindow& window)
     if (m_switcher.is_visible() && window.type() != WSWindowType::WindowSwitcher)
         m_switcher.refresh();
 
+
     recompute_occlusions();
 
     for_each_window_listening_to_wm_events([&window](WSWindow& listener) {
         if (!(listener.wm_event_mask() & WSWMEventMask::WindowRemovals))
             return IterationDecision::Continue;
-        if (window.client())
-            listener.client()->post_message(WindowClient::WM_WindowRemoved(listener.window_id(), window.client()->client_id(), window.window_id()));
+        if (!window.is_internal())
+            listener.client()->post_message(WindowClient::WM_WindowRemoved(listener.window_id(), window.client_id(), window.window_id()));
         return IterationDecision::Continue;
     });
 }
@@ -220,25 +221,25 @@ void WSWindowManager::tell_wm_listener_about_window(WSWindow& listener, WSWindow
 {
     if (!(listener.wm_event_mask() & WSWMEventMask::WindowStateChanges))
         return;
-    if (!window.client())
+    if (window.is_internal())
         return;
-    listener.client()->post_message(WindowClient::WM_WindowStateChanged(listener.window_id(), window.client()->client_id(), window.window_id(), window.is_active(), window.is_minimized(), (i32)window.type(), window.title(), window.rect()));
+    listener.client()->post_message(WindowClient::WM_WindowStateChanged(listener.window_id(), window.client_id(), window.window_id(), window.is_active(), window.is_minimized(), (i32)window.type(), window.title(), window.rect()));
 }
 
 void WSWindowManager::tell_wm_listener_about_window_rect(WSWindow& listener, WSWindow& window)
 {
     if (!(listener.wm_event_mask() & WSWMEventMask::WindowRectChanges))
         return;
-    if (!window.client())
+    if (window.is_internal())
         return;
-    listener.client()->post_message(WindowClient::WM_WindowRectChanged(listener.window_id(), window.client()->client_id(), window.window_id(), window.rect()));
+    listener.client()->post_message(WindowClient::WM_WindowRectChanged(listener.window_id(), window.client_id(), window.window_id(), window.rect()));
 }
 
 void WSWindowManager::tell_wm_listener_about_window_icon(WSWindow& listener, WSWindow& window)
 {
     if (!(listener.wm_event_mask() & WSWMEventMask::WindowIconChanges))
         return;
-    if (!window.client())
+    if (window.is_internal())
         return;
     if (window.icon().shared_buffer_id() == -1)
         return;
@@ -246,7 +247,7 @@ void WSWindowManager::tell_wm_listener_about_window_icon(WSWindow& listener, WSW
     if (share_buffer_with(window.icon().shared_buffer_id(), listener.client()->client_pid()) < 0) {
         ASSERT_NOT_REACHED();
     }
-    listener.client()->post_message(WindowClient::WM_WindowIconBitmapChanged(listener.window_id(), window.client()->client_id(), window.window_id(), window.icon().shared_buffer_id(), window.icon().size()));
+    listener.client()->post_message(WindowClient::WM_WindowIconBitmapChanged(listener.window_id(), window.client_id(), window.window_id(), window.icon().shared_buffer_id(), window.icon().size()));
 }
 
 void WSWindowManager::tell_wm_listeners_window_state_changed(WSWindow& window)