diff --git a/abstract_client.h b/abstract_client.h
--- a/abstract_client.h
+++ b/abstract_client.h
@@ -343,7 +343,24 @@
     }
 
     virtual void updateMouseGrab();
+    /**
+     * @returns The caption consisting of @link{captionNormal} and @link{captionSuffix}
+     * @see captionNormal
+     * @see captionSuffix
+     **/
     virtual QString caption(bool full = true) const = 0;
+    /**
+     * @returns The caption as set by the AbstractClient without any suffix.
+     * @see caption
+     * @see captionSuffix
+     **/
+    virtual QString captionNormal() const = 0;
+    /**
+     * @returns The suffix added to the caption (e.g. shortcut, machine name, etc.)
+     * @see caption
+     * @see captionNormal
+     **/
+    virtual QString captionSuffix() const = 0;
     virtual bool isCloseable() const = 0;
     // TODO: remove boolean trap
     virtual bool isShown(bool shaded_is_shown) const = 0;
@@ -986,6 +1003,12 @@
     QString shortcutCaptionSuffix() const;
     virtual void updateCaption() = 0;
 
+    /**
+     * Looks for another AbstractClient with same @link{captionNormal} and @link{captionSuffix}.
+     * If no such AbstractClient exists @c nullptr is returned.
+     **/
+    AbstractClient *findClientWithSameCaption() const;
+
 private:
     void handlePaletteChange();
     QSharedPointer<TabBox::TabBoxClientImpl> m_tabBoxClient;
diff --git a/abstract_client.cpp b/abstract_client.cpp
--- a/abstract_client.cpp
+++ b/abstract_client.cpp
@@ -1758,4 +1758,12 @@
     return QLatin1String(" {") + shortcut().toString() + QLatin1Char('}');
 }
 
+AbstractClient *AbstractClient::findClientWithSameCaption() const
+{
+    auto fetchNameInternalPredicate = [this](const AbstractClient *cl) {
+        return (!cl->isSpecialWindow() || cl->isToolbar()) && cl != this && cl->captionNormal() == captionNormal() && cl->captionSuffix() == captionSuffix();
+    };
+    return workspace()->findAbstractClient(fetchNameInternalPredicate);
+}
+
 }
diff --git a/autotests/integration/shell_client_test.cpp b/autotests/integration/shell_client_test.cpp
--- a/autotests/integration/shell_client_test.cpp
+++ b/autotests/integration/shell_client_test.cpp
@@ -74,6 +74,7 @@
     void testHidden();
     void testDesktopFileName();
     void testCaptionSimplified();
+    void testCaptionMultipleWindows();
     void testKillWindow_data();
     void testKillWindow();
     void testX11WindowId_data();
@@ -693,6 +694,53 @@
     QCOMPARE(c->caption(), origTitle.simplified());
 }
 
+void TestShellClient::testCaptionMultipleWindows()
+{
+    QScopedPointer<Surface> surface(Test::createSurface());
+    QScopedPointer<XdgShellSurface> shellSurface(qobject_cast<XdgShellSurface*>(Test::createShellSurface(Test::ShellSurfaceType::XdgShellV5, surface.data())));
+    shellSurface->setTitle(QStringLiteral("foo"));
+    auto c = Test::renderAndWaitForShown(surface.data(), QSize(100, 50), Qt::blue);
+    QVERIFY(c);
+    QCOMPARE(c->caption(), QStringLiteral("foo"));
+    QCOMPARE(c->captionNormal(), QStringLiteral("foo"));
+    QCOMPARE(c->captionSuffix(), QString());
+
+    QScopedPointer<Surface> surface2(Test::createSurface());
+    QScopedPointer<XdgShellSurface> shellSurface2(qobject_cast<XdgShellSurface*>(Test::createShellSurface(Test::ShellSurfaceType::XdgShellV5, surface2.data())));
+    shellSurface2->setTitle(QStringLiteral("foo"));
+    auto c2 = Test::renderAndWaitForShown(surface2.data(), QSize(100, 50), Qt::blue);
+    QVERIFY(c2);
+    QCOMPARE(c2->caption(), QStringLiteral("foo <2>"));
+    QCOMPARE(c2->captionNormal(), QStringLiteral("foo"));
+    QCOMPARE(c2->captionSuffix(), QStringLiteral(" <2>"));
+
+    QScopedPointer<Surface> surface3(Test::createSurface());
+    QScopedPointer<XdgShellSurface> shellSurface3(qobject_cast<XdgShellSurface*>(Test::createShellSurface(Test::ShellSurfaceType::XdgShellV5, surface3.data())));
+    shellSurface3->setTitle(QStringLiteral("foo"));
+    auto c3 = Test::renderAndWaitForShown(surface3.data(), QSize(100, 50), Qt::blue);
+    QVERIFY(c3);
+    QCOMPARE(c3->caption(), QStringLiteral("foo <3>"));
+    QCOMPARE(c3->captionNormal(), QStringLiteral("foo"));
+    QCOMPARE(c3->captionSuffix(), QStringLiteral(" <3>"));
+
+    QScopedPointer<Surface> surface4(Test::createSurface());
+    QScopedPointer<XdgShellSurface> shellSurface4(qobject_cast<XdgShellSurface*>(Test::createShellSurface(Test::ShellSurfaceType::XdgShellV5, surface4.data())));
+    shellSurface4->setTitle(QStringLiteral("bar"));
+    auto c4 = Test::renderAndWaitForShown(surface4.data(), QSize(100, 50), Qt::blue);
+    QVERIFY(c4);
+    QCOMPARE(c4->caption(), QStringLiteral("bar"));
+    QCOMPARE(c4->captionNormal(), QStringLiteral("bar"));
+    QCOMPARE(c4->captionSuffix(), QString());
+    QSignalSpy captionChangedSpy(c4, &ShellClient::captionChanged);
+    QVERIFY(captionChangedSpy.isValid());
+    shellSurface4->setTitle(QStringLiteral("foo"));
+    QVERIFY(captionChangedSpy.wait());
+    QCOMPARE(captionChangedSpy.count(), 1);
+    QCOMPARE(c4->caption(), QStringLiteral("foo <4>"));
+    QCOMPARE(c4->captionNormal(), QStringLiteral("foo"));
+    QCOMPARE(c4->captionSuffix(), QStringLiteral(" <4>"));
+}
+
 void TestShellClient::testKillWindow_data()
 {
     QTest::addColumn<bool>("socketMode");
diff --git a/client.h b/client.h
--- a/client.h
+++ b/client.h
@@ -220,6 +220,12 @@
     inline bool isBlockingCompositing() { return blocks_compositing; }
 
     QString caption(bool full = true) const override;
+    QString captionNormal() const override {
+        return cap_normal;
+    }
+    QString captionSuffix() const override {
+        return cap_suffix;
+    }
 
     using AbstractClient::keyPressEvent;
     void keyPressEvent(uint key_code, xcb_timestamp_t time);   // FRAME ??
diff --git a/client.cpp b/client.cpp
--- a/client.cpp
+++ b/client.cpp
@@ -1463,16 +1463,12 @@
     }
     QString shortcut_suffix = shortcutCaptionSuffix();
     cap_suffix = machine_suffix + shortcut_suffix;
-    auto fetchNameInternalPredicate = [this](const Client *cl) {
-        return (!cl->isSpecialWindow() || cl->isToolbar()) &&
-                cl != this && cl->caption() == caption();
-    };
-    if ((!isSpecialWindow() || isToolbar()) && workspace()->findClient(fetchNameInternalPredicate)) {
+    if ((!isSpecialWindow() || isToolbar()) && findClientWithSameCaption()) {
         int i = 2;
         do {
             cap_suffix = machine_suffix + QLatin1String(" <") + QString::number(i) + QLatin1Char('>') + LRM;
             i++;
-        } while (workspace()->findClient(fetchNameInternalPredicate));
+        } while (findClientWithSameCaption());
         info->setVisibleName(caption().toUtf8().constData());
         reset_name = false;
     }
diff --git a/shell_client.h b/shell_client.h
--- a/shell_client.h
+++ b/shell_client.h
@@ -64,6 +64,12 @@
 
     void blockActivityUpdates(bool b = true) override;
     QString caption(bool full = true) const override;
+    QString captionNormal() const override {
+        return m_caption;
+    }
+    QString captionSuffix() const override {
+        return m_captionSuffix;
+    }
     void closeWindow() override;
     AbstractClient *findModal(bool allow_itself = false) override;
     bool isCloseable() const override;
diff --git a/shell_client.cpp b/shell_client.cpp
--- a/shell_client.cpp
+++ b/shell_client.cpp
@@ -104,12 +104,19 @@
 void ShellClient::initSurface(T *shellSurface)
 {
     m_caption = shellSurface->title().simplified();
-    connect(shellSurface, &T::titleChanged, this, &ShellClient::captionChanged);
+    // delay till end of init
+    QTimer::singleShot(0, this, &ShellClient::updateCaption);
     connect(shellSurface, &T::destroyed, this, &ShellClient::destroyClient);
     connect(shellSurface, &T::titleChanged, this,
         [this] (const QString &s) {
+            const auto oldSuffix = m_captionSuffix;
             m_caption = s.simplified();
-            emit captionChanged();
+            updateCaption();
+            if (m_captionSuffix == oldSuffix) {
+                // don't emit caption change twice
+                // it already got emitted by the changing suffix
+                emit captionChanged();
+            }
         }
     );
     connect(shellSurface, &T::moveRequested, this,
@@ -571,7 +578,15 @@
 void ShellClient::updateCaption()
 {
     const QString oldSuffix = m_captionSuffix;
-    m_captionSuffix = shortcutCaptionSuffix();
+    const auto shortcut = shortcutCaptionSuffix();
+    m_captionSuffix = shortcut;
+    if ((!isSpecialWindow() || isToolbar()) && findClientWithSameCaption()) {
+        int i = 2;
+        do {
+            m_captionSuffix = shortcut + QLatin1String(" <") + QString::number(i) + QLatin1Char('>');
+            i++;
+        } while (findClientWithSameCaption());
+    }
     if (m_captionSuffix != oldSuffix) {
         emit captionChanged();
     }