diff --git a/src/abstract_client.cpp b/src/abstract_client.cpp
index 453f0d1899..ddc40574c0 100644
--- a/src/abstract_client.cpp
+++ b/src/abstract_client.cpp
@@ -2707,11 +2707,15 @@ void AbstractClient::setDesktopFileName(QByteArray name)
 
 QString AbstractClient::iconFromDesktopFile() const
 {
-    if (m_desktopFileName.isEmpty()) {
+    return iconFromDesktopFile(QFile::decodeName(m_desktopFileName));
+}
+
+QString AbstractClient::iconFromDesktopFile(const QString &desktopFileName)
+{
+    if (desktopFileName.isEmpty()) {
         return {};
     }
 
-    const QString desktopFileName = QString::fromUtf8(m_desktopFileName);
     QString desktopFilePath;
 
     if (QDir::isAbsolutePath(desktopFileName)) {
@@ -2726,6 +2730,9 @@ QString AbstractClient::iconFromDesktopFile() const
         desktopFilePath = QStandardPaths::locate(QStandardPaths::ApplicationsLocation,
                                                  desktopFileName + QLatin1String(".desktop"));
     }
+    if (desktopFilePath.isEmpty()) {
+        return {};
+    }
 
     KDesktopFile df(desktopFilePath);
     return df.readIcon();
diff --git a/src/abstract_client.h b/src/abstract_client.h
index 4e68465a4b..3bd7a4399f 100644
--- a/src/abstract_client.h
+++ b/src/abstract_client.h
@@ -878,6 +878,13 @@ public:
 
     QRect fullscreenGeometryRestore() const;
 
+    /**
+     * Helper function to compute the icon out of an application id defined by @p fileName
+     *
+     * @returns an icon name that can be used with QIcon::fromTheme()
+     */
+    static QString iconFromDesktopFile(const QString &fileName);
+
 public Q_SLOTS:
     virtual void closeWindow() = 0;