diff --git a/GUI/View/Project/SimulationView.h b/GUI/View/Project/SimulationView.h
index b79c36166b942fcc959752dc3859c1032ec12645..b07d6503139d5c22f32828e53b4462a6f151b2b9 100644
--- a/GUI/View/Project/SimulationView.h
+++ b/GUI/View/Project/SimulationView.h
@@ -17,12 +17,12 @@
 
 #include <QComboBox>
 
-class MainWindow;
-class SampleItem;
 class InstrumentItem;
+class MainWindow;
+class ProjectDocument;
 class RealItem;
+class SampleItem;
 class SimulationOptionsItem;
-class ProjectDocument;
 
 namespace Ui {