diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 7d511bf0d7..da3879cb56 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -1351,7 +1351,8 @@ void QWindowsWindow::destroyWindow()
         for (QWindow *w : tlw) {
             if (w->transientParent() == window()) {
                 if (QWindowsWindow *tw = QWindowsWindow::windowsWindowOf(w))
-                    tw->updateTransientParent();
+                    // Patch: Fix possibility of add / remove taskbar icon of the window.
+                    tw->clearTransientParent();
             }
         }
         QWindowsContext *context = QWindowsContext::instance();
@@ -1579,6 +1580,19 @@ void QWindowsWindow::updateTransientParent() const
     // window is found, which can cause issues with modality. Loop up to top level.
     while (newTransientParent && (GetWindowLongPtr(newTransientParent, GWL_STYLE) & WS_CHILD) != 0)
         newTransientParent = GetParent(newTransientParent);
+    // Patch: Fix possibility of add / remove taskbar icon of the window.
+    if (newTransientParent && newTransientParent != oldTransientParent)
+        SetWindowLongPtr(m_data.hwnd, GWL_HWNDPARENT, (LONG_PTR)newTransientParent);
+}
+
+// Patch: Fix possibility of add / remove taskbar icon of the window.
+void QWindowsWindow::clearTransientParent() const
+{
+    if (window()->type() == Qt::Popup)
+        return; // QTBUG-34503, // a popup stays on top, no parent, see also WindowCreationData::fromWindow().
+    // Update transient parent.
+    const HWND oldTransientParent = GetWindow(m_data.hwnd, GW_OWNER);
+    HWND newTransientParent = 0;
 
     if (newTransientParent != oldTransientParent)
         SetWindowLongPtr(m_data.hwnd, GWL_HWNDPARENT, LONG_PTR(newTransientParent));
diff --git a/src/plugins/platforms/windows/qwindowswindow.h b/src/plugins/platforms/windows/qwindowswindow.h
index ce67e46df3..a60edc151f 100644
--- a/src/plugins/platforms/windows/qwindowswindow.h
+++ b/src/plugins/platforms/windows/qwindowswindow.h
@@ -353,6 +353,10 @@ private:
     inline void setWindowState_sys(Qt::WindowStates newState);
     inline void setParent_sys(const QPlatformWindow *parent);
     inline void updateTransientParent() const;
+
+    // Patch: Fix possibility of add / remove taskbar icon of the window.
+    inline void clearTransientParent() const;
+
     void destroyWindow();
     inline bool isDropSiteEnabled() const { return m_dropTarget != 0; }
     void setDropSiteEnabled(bool enabled);