diff --git a/GUI/Model/FromCore/ItemizeSimulation.cpp b/GUI/Model/FromCore/ItemizeSimulation.cpp
index ddbeafae212ff1e7cbb259f210345f7341cbce7c..e81124b1ff37944a170201dab932316b30b68fd4 100644
--- a/GUI/Model/FromCore/ItemizeSimulation.cpp
+++ b/GUI/Model/FromCore/ItemizeSimulation.cpp
@@ -35,7 +35,6 @@
 #include "GUI/Model/Detector/OffspecDetectorItem.h"
 #include "GUI/Model/Detector/ResolutionFunctionItems.h"
 #include "GUI/Model/Mask/MasksSet.h"
-#include "GUI/Model/Sim/BackgroundItems.h"
 #include "GUI/Model/Sim/InstrumentsSet.h"
 #include "GUI/Model/Sim/SimulationOptionsItem.h"
 #include "Param/Distrib/Distributions.h"
diff --git a/GUI/Model/Job/ParameterTreeBuilder.cpp b/GUI/Model/Job/ParameterTreeBuilder.cpp
index 47373ed84e3270001529c1d739b37fee36bd6a1d..2fd0171a08759bade11e4bcb5804acc7e4fdf5cd 100644
--- a/GUI/Model/Job/ParameterTreeBuilder.cpp
+++ b/GUI/Model/Job/ParameterTreeBuilder.cpp
@@ -31,7 +31,6 @@
 #include "GUI/Model/Sample/ParticleLayoutItem.h"
 #include "GUI/Model/Sample/RoughnessItems.h"
 #include "GUI/Model/Sample/SampleItem.h"
-#include "GUI/Model/Sim/BackgroundItems.h"
 #include "GUI/Model/Sim/InstrumentItems.h"
 
 using std::variant;
diff --git a/GUI/Model/Sim/InstrumentItems.h b/GUI/Model/Sim/InstrumentItems.h
index 2cb2628a748536c4514f674d0e4aff52aa8a7673..146f77ff516a958ecc1d94aba6a71889685e997a 100644
--- a/GUI/Model/Sim/InstrumentItems.h
+++ b/GUI/Model/Sim/InstrumentItems.h
@@ -19,10 +19,10 @@
 #include "GUI/Model/Descriptor/PolyPtr.h"
 #include "GUI/Model/Descriptor/VectorProperty.h"
 #include "GUI/Model/Sim/BackgroundCatalog.h"
+#include "GUI/Model/Sim/BackgroundItems.h"
 #include "GUI/Model/Type/NamedItem.h"
 #include <memory>
 
-class BackgroundItem;
 class BeamItem;
 class DatafileItem;
 class DetectorItem;