diff --git a/abstract_client.h b/abstract_client.h
--- a/abstract_client.h
+++ b/abstract_client.h
@@ -244,6 +244,17 @@
      * Because of that there is no notify signal.
      **/
     Q_PROPERTY(bool resizeable READ isResizable)
+
+    /**
+     * The desktop file name of the application this AbstractClient belongs to.
+     *
+     * This is either the base name without full path and without file extension of the
+     * desktop file for the window's application (e.g. "org.kde.foo").
+     *
+     * The application's desktop file name can also be the full path to the desktop file
+     * (e.g. "/opt/kde/share/org.kde.foo.desktop") in case it's not in a standard location.
+     **/
+    Q_PROPERTY(QByteArray desktopFileName READ desktopFileName NOTIFY desktopFileNameChanged)
 public:
     virtual ~AbstractClient();
 
@@ -599,6 +610,10 @@
      **/
     virtual void showOnScreenEdge() = 0;
 
+    QByteArray desktopFileName() const {
+        return m_desktopFileName;
+    }
+
     // TODO: remove boolean trap
     static bool belongToSameApplication(const AbstractClient* c1, const AbstractClient* c2, bool active_hack = false);
 
@@ -640,6 +655,7 @@
     void minimizeableChanged(bool);
     void shadeableChanged(bool);
     void maximizeableChanged(bool);
+    void desktopFileNameChanged();
 
 protected:
     AbstractClient();
@@ -918,6 +934,9 @@
     void startDecorationDoubleClickTimer();
     void invalidateDecorationDoubleClickTimer();
 
+    void setDesktopFileName(const QByteArray &name);
+    QString iconFromDesktopFile() const;
+
 private:
     void handlePaletteChange();
     QSharedPointer<TabBox::TabBoxClientImpl> m_tabBoxClient;
@@ -985,6 +1004,8 @@
         QElapsedTimer doubleClickTimer;
     } m_decoration;
 
+    QByteArray m_desktopFileName;
+
 
     static bool s_haveResizeEffect;
 };
diff --git a/abstract_client.cpp b/abstract_client.cpp
--- a/abstract_client.cpp
+++ b/abstract_client.cpp
@@ -39,6 +39,8 @@
 
 #include <KDecoration2/Decoration>
 
+#include <KDesktopFile>
+
 #include <QMouseEvent>
 #include <QStyleHints>
 
@@ -674,7 +676,10 @@
     w->setMinimizeable(isMinimizable());
     w->setFullscreenable(isFullScreenable());
     w->setIcon(icon());
-    w->setAppId(QString::fromUtf8(resourceName()));
+    auto updateAppId = [this, w] {
+        w->setAppId(QString::fromUtf8(m_desktopFileName.isEmpty() ? resourceName() : m_desktopFileName));
+    };
+    updateAppId();
     w->setSkipTaskbar(skipTaskbar());
     w->setShadeable(isShadeable());
     w->setShaded(isShade());
@@ -716,11 +721,8 @@
             w->setIcon(icon());
         }
     );
-    connect(this, &AbstractClient::windowClassChanged, w,
-        [w, this] {
-            w->setAppId(QString::fromUtf8(resourceName()));
-        }
-    );
+    connect(this, &AbstractClient::windowClassChanged, w, updateAppId);
+    connect(this, &AbstractClient::desktopFileNameChanged, w, updateAppId);
     connect(this, &AbstractClient::shadeChanged, w, [w, this] { w->setShaded(isShade()); });
     connect(this, &AbstractClient::transientChanged, w,
         [w, this] {
@@ -1639,4 +1641,26 @@
     return false;
 }
 
+void AbstractClient::setDesktopFileName(const QByteArray &name)
+{
+    if (name == m_desktopFileName) {
+        return;
+    }
+    m_desktopFileName = name;
+    emit desktopFileNameChanged();
+}
+
+QString AbstractClient::iconFromDesktopFile() const
+{
+    if (m_desktopFileName.isEmpty()) {
+        return QString();
+    }
+    QString desktopFile = QString::fromUtf8(m_desktopFileName);
+    if (!desktopFile.endsWith(QLatin1String(".desktop"))) {
+        desktopFile.append(QLatin1String(".desktop"));
+    }
+    KDesktopFile df(desktopFile);
+    return df.readIcon();
+}
+
 }
diff --git a/autotests/integration/data/example.desktop b/autotests/integration/data/example.desktop
new file mode 100644
--- /dev/null
+++ b/autotests/integration/data/example.desktop
@@ -0,0 +1,3 @@
+[Desktop Entry]
+Name=An example application
+Icon=kwin
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
@@ -62,6 +62,7 @@
     void testWindowOpensLargerThanScreen();
     void testHidden_data();
     void testHidden();
+    void testDesktopFileName();
 };
 
 void TestShellClient::initTestCase()
@@ -583,5 +584,37 @@
     //QCOMPARE(workspace()->activeClient(), c);
 }
 
+void TestShellClient::testDesktopFileName()
+{
+    // this test verifies that desktop file name is passed correctly to the window
+    QScopedPointer<Surface> surface(Test::createSurface());
+    // only xdg-shell as ShellSurface misses the setter
+    QScopedPointer<XdgShellSurface> shellSurface(qobject_cast<XdgShellSurface*>(Test::createShellSurface(Test::ShellSurfaceType::XdgShellV5, surface.data())));
+    shellSurface->setAppId(QByteArrayLiteral("org.kde.foo"));
+    auto c = Test::renderAndWaitForShown(surface.data(), QSize(100, 50), Qt::blue);
+    QVERIFY(c);
+    QCOMPARE(c->desktopFileName(), QByteArrayLiteral("org.kde.foo"));
+    // the desktop file does not exist, so icon should be generic Wayland
+    QCOMPARE(c->icon().name(), QStringLiteral("wayland"));
+
+    QSignalSpy desktopFileNameChangedSpy(c, &AbstractClient::desktopFileNameChanged);
+    QVERIFY(desktopFileNameChangedSpy.isValid());
+    QSignalSpy iconChangedSpy(c, &ShellClient::iconChanged);
+    QVERIFY(iconChangedSpy.isValid());
+    shellSurface->setAppId(QByteArrayLiteral("org.kde.bar"));
+    QVERIFY(desktopFileNameChangedSpy.wait());
+    QCOMPARE(c->desktopFileName(), QByteArrayLiteral("org.kde.bar"));
+    // icon should still be wayland
+    QCOMPARE(c->icon().name(), QStringLiteral("wayland"));
+    QVERIFY(iconChangedSpy.isEmpty());
+
+    const QString dfPath = QFINDTESTDATA("data/example.desktop");
+    shellSurface->setAppId(dfPath.toUtf8());
+    QVERIFY(desktopFileNameChangedSpy.wait());
+    QCOMPARE(iconChangedSpy.count(), 1);
+    QCOMPARE(QString::fromUtf8(c->desktopFileName()), dfPath);
+    QCOMPARE(c->icon().name(), QStringLiteral("kwin"));
+}
+
 WAYLANDTEST_MAIN(TestShellClient)
 #include "shell_client_test.moc"
diff --git a/client.cpp b/client.cpp
--- a/client.cpp
+++ b/client.cpp
@@ -1683,6 +1683,11 @@
 void Client::getIcons()
 {
     // First read icons from the window itself
+    const QString themedIconName = iconFromDesktopFile();
+    if (!themedIconName.isEmpty()) {
+        setIcon(QIcon::fromTheme(themedIconName));
+        return;
+    }
     QIcon icon;
     auto readIcon = [this, &icon](int size, bool scale = true) {
         const QPixmap pix = KWindowSystem::icon(window(), size, size, scale, KWindowSystem::NETWM | KWindowSystem::WMHints, info);
diff --git a/events.cpp b/events.cpp
--- a/events.cpp
+++ b/events.cpp
@@ -651,6 +651,9 @@
         if (dirtyProperties2 & NET::WM2OpaqueRegion) {
             getWmOpaqueRegion();
         }
+        if (dirtyProperties2 & NET::WM2DesktopFileName) {
+            setDesktopFileName(QByteArray(info->desktopFileName()));
+        }
     }
 
     const uint8_t eventType = e->response_type & ~0x80;
diff --git a/manage.cpp b/manage.cpp
--- a/manage.cpp
+++ b/manage.cpp
@@ -93,7 +93,8 @@
         NET::WM2Protocols |
         NET::WM2InitialMappingState |
         NET::WM2IconPixmap |
-        NET::WM2OpaqueRegion;
+        NET::WM2OpaqueRegion |
+        NET::WM2DesktopFileName;
 
     auto wmClientLeaderCookie = fetchWmClientLeader();
     auto skipCloseAnimationCookie = fetchSkipCloseAnimation();
@@ -142,7 +143,10 @@
 
     setModal((info->state() & NET::Modal) != 0);   // Needs to be valid before handling groups
     readTransientProperty(transientCookie);
+    setDesktopFileName(QByteArray(info->desktopFileName()));
     getIcons();
+    connect(this, &Client::desktopFileNameChanged, this, &Client::getIcons);
+
     m_geometryHints.read();
     getMotifHints();
     getWmOpaqueRegion();
diff --git a/shell_client.cpp b/shell_client.cpp
--- a/shell_client.cpp
+++ b/shell_client.cpp
@@ -108,12 +108,13 @@
             performMouseCommand(Options::MouseMove, Cursor::pos());
         }
     );
-    connect(shellSurface, &T::windowClassChanged, this, &ShellClient::updateIcon);
 
     setResourceClass(shellSurface->windowClass());
+    setDesktopFileName(shellSurface->windowClass());
     connect(shellSurface, &T::windowClassChanged, this,
         [this] (const QByteArray &windowClass) {
             setResourceClass(windowClass);
+            setDesktopFileName(windowClass);
         }
     );
     connect(shellSurface, &T::resizeRequested, this,
@@ -168,6 +169,7 @@
 
 void ShellClient::init()
 {
+    connect(this, &ShellClient::desktopFileNameChanged, this, &ShellClient::updateIcon);
     findInternalWindow();
     createWindowId();
     setupCompositing();
@@ -233,7 +235,6 @@
     } else if (m_xdgShellPopup) {
         connect(m_xdgShellPopup, &XdgShellPopupInterface::destroyed, this, &ShellClient::destroyClient);
     }
-    updateIcon();
 
     // setup shadow integration
     getShadow();
@@ -1184,19 +1185,12 @@
 void ShellClient::updateIcon()
 {
     const QString waylandIconName = QStringLiteral("wayland");
-    QString desktopFile;
-    if (m_shellSurface) {
-        desktopFile = QString::fromUtf8(m_shellSurface->windowClass());
-    }
-    if (desktopFile.isEmpty()) {
-        setIcon(QIcon::fromTheme(waylandIconName));
-    }
-    if (!desktopFile.endsWith(QLatin1String(".desktop"))) {
-        desktopFile.append(QLatin1String(".desktop"));
+    const QString dfIconName = iconFromDesktopFile();
+    const QString iconName = dfIconName.isEmpty() ? waylandIconName : dfIconName;
+    if (iconName == icon().name()) {
+        return;
     }
-    KDesktopFile df(desktopFile);
-    const QString iconName = df.readIcon();
-    setIcon(QIcon::fromTheme(iconName.isEmpty() ? waylandIconName : iconName));
+    setIcon(QIcon::fromTheme(iconName));
 }
 
 bool ShellClient::isTransient() const