diff --git a/src/widgets/widgets/qdockwidget.cpp b/src/widgets/widgets/qdockwidget.cpp
index 33e9c8f3e88..aa4b4441859 100644
--- a/src/widgets/widgets/qdockwidget.cpp
+++ b/src/widgets/widgets/qdockwidget.cpp
@@ -1359,6 +1359,8 @@ QDockWidget::QDockWidget(const QString &title, QWidget *parent, Qt::WindowFlags
 */
 QDockWidget::~QDockWidget()
 {
+    Q_D(QDockWidget);
+    d->inDestructor = true;
     // Do all the unregistering while we're still a QDockWidget. Otherwise, it
     // would be ~QObject() which does that and then QDockAreaLayout::takeAt(),
     // acting on QEvent::ChildRemoved, will try to access our QWidget-ness when
@@ -1645,8 +1647,12 @@ bool QDockWidget::event(QEvent *event)
     case QEvent::Hide:
         if (layout != nullptr)
             layout->keepSize(this);
-        d->toggleViewAction->setChecked(false);
-        emit visibilityChanged(false);
+        // If we are in the destructor, don't emit any signals, as those might
+        // be handled by a slot that requires this dock widget to still be alive.
+        if (!d->inDestructor) {
+            d->toggleViewAction->setChecked(false);
+            emit visibilityChanged(false);
+        }
         break;
     case QEvent::Show: {
         d->toggleViewAction->setChecked(true);
diff --git a/src/widgets/widgets/qdockwidget_p.h b/src/widgets/widgets/qdockwidget_p.h
index 15544280669..477f1a4b83e 100644
--- a/src/widgets/widgets/qdockwidget_p.h
+++ b/src/widgets/widgets/qdockwidget_p.h
@@ -94,6 +94,7 @@ public:
     QRect undockedGeometry;
     QString fixedWindowTitle;
     QString dockedWindowTitle;
+    bool inDestructor = false;
 
     bool mousePressEvent(QMouseEvent *event);
     bool mouseDoubleClickEvent(QMouseEvent *event);
diff --git a/tests/auto/widgets/widgets/qdockwidget/tst_qdockwidget.cpp b/tests/auto/widgets/widgets/qdockwidget/tst_qdockwidget.cpp
index e7c6bc1cff5..9fe4dcec7f0 100644
--- a/tests/auto/widgets/widgets/qdockwidget/tst_qdockwidget.cpp
+++ b/tests/auto/widgets/widgets/qdockwidget/tst_qdockwidget.cpp
@@ -46,6 +46,8 @@ private slots:
     void allowedAreas();
     void toggleViewAction();
     void visibilityChanged();
+    void visibilityChangedOnDestruction_data();
+    void visibilityChangedOnDestruction();
     void updateTabBarOnVisibilityChanged();
     void dockLocationChanged();
     void setTitleBarWidget();
@@ -717,6 +719,45 @@ void tst_QDockWidget::visibilityChanged()
     QCOMPARE(spy.at(0).at(0).toBool(), true);
 }
 
+// QTBUG-136485 - QDockWidget didn't emit visibilityChanged when getting
+// destroyed until 6.9.0; it did in 6.9.0, causing regressions in applications.
+// So make sure we don't emit that signal when a QDockWidget gets destroyed.
+// When implicitly destroyed as a child of a QMainWindow, it gets hidden first,
+// so it emits the signal.
+void tst_QDockWidget::visibilityChangedOnDestruction_data()
+{
+    QTest::addColumn<bool>("explicitDestroy");
+    QTest::addColumn<bool>("floating");
+    QTest::addColumn<int>("signalCount");
+
+    QTest::addRow("Explicit, docked") << true << false << 0;
+    QTest::addRow("Explicit, floating") << true << true << 0;
+    QTest::addRow("Implicit, docked") << false << false << 1;
+    QTest::addRow("Implicit, floating") << false << true << 0;
+}
+
+void tst_QDockWidget::visibilityChangedOnDestruction()
+{
+    QFETCH(const bool, explicitDestroy);
+    QFETCH(const bool, floating);
+    QFETCH(const int, signalCount);
+
+    std::unique_ptr<QMainWindow> mw(new QMainWindow);
+    QDockWidget *dw = new QDockWidget;
+    mw->addDockWidget(Qt::LeftDockWidgetArea, dw);
+    if (floating)
+        dw->setFloating(true);
+    mw->show();
+    QVERIFY(QTest::qWaitForWindowExposed(mw.get()));
+
+    QSignalSpy spy(dw, &QDockWidget::visibilityChanged);
+    if (explicitDestroy)
+        delete dw;
+    else
+        mw.reset();
+    QCOMPARE(spy.count(), signalCount);
+}
+
 void tst_QDockWidget::updateTabBarOnVisibilityChanged()
 {
     // QTBUG49045: Populate tabified dock area with 4 widgets, set the tab