diff --git a/libguh/plugin/deviceplugin.h b/libguh/plugin/deviceplugin.h
index 38427f3e..5a0d9aad 100644
--- a/libguh/plugin/deviceplugin.h
+++ b/libguh/plugin/deviceplugin.h
@@ -67,7 +67,7 @@ public slots:
 
 signals:
     void emitEvent(const Event &event);
-    void devicesDiscovered(const DeviceClassId &deviceClassId, const QList<DeviceDescriptor> deviceDescriptors);
+    void devicesDiscovered(const DeviceClassId &deviceClassId, const QList<DeviceDescriptor> &deviceDescriptors);
 
 protected:
     DeviceManager *deviceManager() const;