diff --git a/library/SolverUtils/Core/SessionFunction.cpp b/library/SolverUtils/Core/SessionFunction.cpp
index f8c5bed3508a37edd1377b5b3914a80c50b84e1a..6ba657d611dedf77d538f1a9ed5d6a9d583f6671 100644
--- a/library/SolverUtils/Core/SessionFunction.cpp
+++ b/library/SolverUtils/Core/SessionFunction.cpp
@@ -34,6 +34,7 @@
 //
 ////////////////////////////////////////////////////////////////////////////////
 
+#include <FieldUtils/Interpolator.h>
 #include <SolverUtils/Core/SessionFunction.h>
 
 #include <LibUtilities/BasicUtils/VmathArray.hpp>
diff --git a/library/SolverUtils/Core/SessionFunction.h b/library/SolverUtils/Core/SessionFunction.h
index e077f3c397a4b42401494b698dac5dc91f9b49fe..7d0310965ffa5509b108d1ae5fb70fa167f66db2 100644
--- a/library/SolverUtils/Core/SessionFunction.h
+++ b/library/SolverUtils/Core/SessionFunction.h
@@ -37,7 +37,6 @@
 #ifndef NEKTAR_SOLVERUTILS_SESSIONFUNCTION_H
 #define NEKTAR_SOLVERUTILS_SESSIONFUNCTION_H
 
-#include <FieldUtils/Interpolator.h>
 #include <LibUtilities/BasicUtils/FieldIO.h>
 #include <LibUtilities/BasicUtils/FileSystem.h>
 #include <LibUtilities/BasicUtils/NekFactory.hpp>
@@ -51,6 +50,11 @@
 
 namespace Nektar
 {
+namespace FieldUtils
+{
+class Interpolator;
+}
+
 namespace SolverUtils
 {
 
diff --git a/library/SolverUtils/EquationSystem.h b/library/SolverUtils/EquationSystem.h
index fc0063a52cbb19e720d33919665e6a4fd2cec12e..0f34d2a4fccc7eef1ccee247f2f5b40801ad145d 100644
--- a/library/SolverUtils/EquationSystem.h
+++ b/library/SolverUtils/EquationSystem.h
@@ -36,6 +36,7 @@
 #ifndef NEKTAR_SOLVERUTILS_EQUATIONSYSTEM_H
 #define NEKTAR_SOLVERUTILS_EQUATIONSYSTEM_H
 
+#include <SolverUtils/Core/SessionFunction.h>
 #include <LibUtilities/Communication/Comm.h>
 #include <LibUtilities/BasicUtils/SessionReader.h>
 #include <LibUtilities/BasicUtils/NekFactory.hpp>
@@ -48,7 +49,6 @@
 #include <MultiRegions/ExpList.h>
 #include <SolverUtils/SolverUtilsDeclspec.h>
 #include <SolverUtils/Core/Misc.h>
-#include <SolverUtils/Core/SessionFunction.h>
 
 namespace Nektar
 {
diff --git a/library/SolverUtils/Forcing/Forcing.cpp b/library/SolverUtils/Forcing/Forcing.cpp
index dc2c0da7911717cc7f2eada892cbc0eaa03be2a4..7889c91bbdd42a1fa18fd1d8328ba48e4c26e6ba 100644
--- a/library/SolverUtils/Forcing/Forcing.cpp
+++ b/library/SolverUtils/Forcing/Forcing.cpp
@@ -33,6 +33,7 @@
 //
 ///////////////////////////////////////////////////////////////////////////////
 
+#include <FieldUtils/Interpolator.h>
 #include <SolverUtils/Forcing/Forcing.h>
 
 using namespace std;