diff --git a/Core/Computation/DepthProbeComputationTerm.cpp b/Core/Computation/DepthProbeComputationTerm.cpp
index ab5238f7b6d542ec6e6a4cd0e04c61816d605006..792e78de69ca68df789519dec68d4daea1c9ebf8 100644
--- a/Core/Computation/DepthProbeComputationTerm.cpp
+++ b/Core/Computation/DepthProbeComputationTerm.cpp
@@ -18,6 +18,7 @@
 #include "Core/Computation/DepthProbeElement.h"
 #include "Core/Computation/ProcessedSample.h"
 #include "Sample/Fresnel/IFresnelMap.h"
+#include "Sample/RT/ILayerRTCoefficients.h"
 
 DepthProbeComputationTerm::DepthProbeComputationTerm(const ProcessedSample* p_sample)
     : mp_sample{p_sample}
diff --git a/Core/Computation/GISASSpecularComputation.cpp b/Core/Computation/GISASSpecularComputation.cpp
index e534e6c2439c31a99c7c36bc1884a6900814a8b4..7fd23a2d7d79710108a8b57587b6ca4ad1cb3a0e 100644
--- a/Core/Computation/GISASSpecularComputation.cpp
+++ b/Core/Computation/GISASSpecularComputation.cpp
@@ -15,6 +15,7 @@
 #include "Core/Computation/GISASSpecularComputation.h"
 #include "Base/Pixel/SimulationElement.h"
 #include "Sample/Fresnel/IFresnelMap.h"
+#include "Sample/RT/ILayerRTCoefficients.h"
 
 GISASSpecularComputation::GISASSpecularComputation(const IFresnelMap* p_fresnel_map)
     : mp_fresnel_map{p_fresnel_map}
diff --git a/Core/Computation/RoughMultiLayerComputation.cpp b/Core/Computation/RoughMultiLayerComputation.cpp
index bcf435fcb2c8cc23a5fadc824c841b4827d64748..0b5b58330e6453d89d48efc48d4f94d25053a735 100644
--- a/Core/Computation/RoughMultiLayerComputation.cpp
+++ b/Core/Computation/RoughMultiLayerComputation.cpp
@@ -20,6 +20,7 @@
 #include "Sample/Multilayer/Layer.h"
 #include "Sample/Multilayer/LayerInterface.h"
 #include "Sample/Multilayer/MultiLayer.h"
+#include "Sample/RT/ILayerRTCoefficients.h"
 #include "Sample/Slice/LayerRoughness.h"
 
 #include <cerf>
diff --git a/Core/Computation/SpecularComputationTerm.cpp b/Core/Computation/SpecularComputationTerm.cpp
index 1e9eedd9d6b9c69251a4392562d73dacdcd3b2a4..1bca179fcddc030f27776fc5fd8524814c5eaf9c 100644
--- a/Core/Computation/SpecularComputationTerm.cpp
+++ b/Core/Computation/SpecularComputationTerm.cpp
@@ -14,6 +14,7 @@
 
 #include "Core/Computation/SpecularComputationTerm.h"
 #include "Core/Computation/DelayedProgressCounter.h"
+#include "Sample/RT/ILayerRTCoefficients.h"
 #include "Sample/Specular/ISpecularStrategy.h"
 #include "Sample/Specular/SpecularSimulationElement.h"
 
diff --git a/Sample/Fresnel/FormFactorCoherentPart.cpp b/Sample/Fresnel/FormFactorCoherentPart.cpp
index d026f2adb92287eaeba2fac564a1dd3d5885c39d..7e68766613528fc95b7583ba9873b071021a0e21 100644
--- a/Sample/Fresnel/FormFactorCoherentPart.cpp
+++ b/Sample/Fresnel/FormFactorCoherentPart.cpp
@@ -16,6 +16,7 @@
 #include "Base/Pixel/SimulationElement.h"
 #include "Sample/Fresnel/IFresnelMap.h"
 #include "Sample/Material/WavevectorInfo.h"
+#include "Sample/RT/ILayerRTCoefficients.h"
 #include "Sample/Scattering/IFormFactor.h"
 
 FormFactorCoherentPart::FormFactorCoherentPart(IFormFactor* p_ff) : mP_ff(p_ff) {}
diff --git a/Sample/Specular/ISpecularStrategy.h b/Sample/Specular/ISpecularStrategy.h
index c15e8f96ef8018025ea516ba353f6cd40a6bfaa7..2276f0f6622ee1e597542d440696eb224dc9ef7e 100644
--- a/Sample/Specular/ISpecularStrategy.h
+++ b/Sample/Specular/ISpecularStrategy.h
@@ -15,11 +15,12 @@
 #ifndef BORNAGAIN_CORE_MULTILAYER_ISPECULARSTRATEGY_H
 #define BORNAGAIN_CORE_MULTILAYER_ISPECULARSTRATEGY_H
 
+#include "Base/Types/Complex.h"
 #include "Base/Vector/Vectors3D.h"
-#include "Sample/RT/ILayerRTCoefficients.h"
 #include <memory>
 #include <vector>
 
+class ILayerRTCoefficients;
 class Slice;
 
 //! Interface for the Fresnel computations, both in the scalar and magnetic case