diff --git a/Modules/DiffusionImaging/Algorithms/itkTractsToDWIImageFilter.h b/Modules/DiffusionImaging/Algorithms/itkTractsToDWIImageFilter.h
index c39faed42a..b9074f0d4c 100644
--- a/Modules/DiffusionImaging/Algorithms/itkTractsToDWIImageFilter.h
+++ b/Modules/DiffusionImaging/Algorithms/itkTractsToDWIImageFilter.h
@@ -1,105 +1,106 @@
 /*=========================================================================
 
 Program:   Medical Imaging & Interaction Toolkit
 Module:    $RCSfile$
 Language:  C++
 Date:      $Date$
 Version:   $Revision$
 
 Copyright (c) German Cancer Research Center, Division of Medical and
 Biological Informatics. All rights reserved.
 See MITKCopyright.txt or http://www.mitk.org/copyright.html for details.
 
 This software is distributed WITHOUT ANY WARRANTY; without even
 the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 PURPOSE.  See the above copyright notices for more information.
 
 =========================================================================*/
 #ifndef __itkTractsToDWIImageFilter_h__
 #define __itkTractsToDWIImageFilter_h__
 
 // MITK
 #include <mitkParticle.h>
 #include <mitkParticleGrid.h>
 #include <mitkFiberBundle.h>
+#include "MitkDiffusionImagingExports.h"
 
 // ITK
 #include <itkImage.h>
 #include <itkProcessObject.h>
 #include <itkImageToImageFilter.h>
 #include <itkOrientationDistributionFunction.h>
 
 typedef itk::VectorImage< short, 3 > DWIImageType;
 
 namespace itk
 {
-  class TractsToDWIImageFilter :
+  class MitkDiffusionImaging_EXPORT TractsToDWIImageFilter :
       public ImageToImageFilter< DWIImageType, DWIImageType >{
 
   public:
     typedef TractsToDWIImageFilter Self;
     typedef ImageToImageFilter< DWIImageType, DWIImageType > Superclass;
     typedef SmartPointer< Self > Pointer;
     typedef SmartPointer< const Self > ConstPointer;
 
     typedef itk::VectorContainer< int, mitk::Particle* > ParticleContainerType;
     typedef mitk::ParticleGrid::Pointer ParticleGridType;
 
     typedef mitk::FiberBundle::Pointer FiberBundleType;
 
     typedef vnl_vector_fixed< double, 3 > GradientDirectionType;
     typedef itk::VectorContainer< unsigned int,  GradientDirectionType > GradientDirectionContainerType;
 
     itkNewMacro(Self);
     itkTypeMacro( TractsToDWIImageFilter, ImageToImageFilter );
 
     // odf type
     typedef OrientationDistributionFunction<float, QBALL_ODFSIZE> OdfType;
 
     itkSetMacro(FiberBundle, FiberBundleType);
     itkGetMacro(FiberBundle, FiberBundleType);
 
     itkSetMacro(ParticleGrid, ParticleGridType);
     itkGetMacro(ParticleGrid, ParticleGridType);
 
     itkSetMacro(bD, int);
     itkGetMacro(bD, int);
 
     itkSetMacro(ParticleWidth, float);
     itkGetMacro(ParticleWidth, float);
 
     itkSetMacro(ParticleLength, float);
     itkGetMacro(ParticleLength, float);
 
     itkSetMacro(ParticleWeight, float);
     itkGetMacro(ParticleWeight, float);
 
     itkSetMacro(GradientDirections, GradientDirectionContainerType::Pointer);
     itkGetMacro(GradientDirections, GradientDirectionContainerType::Pointer);
 
     void GenerateData();
 
   protected:
 
     TractsToDWIImageFilter();
     virtual ~TractsToDWIImageFilter();
 
     GradientDirectionContainerType::Pointer m_GradientDirections;
     FiberBundleType m_FiberBundle;
     ParticleGridType m_ParticleGrid;
     DWIImageType::Pointer m_OutImage;
     int m_Size[3];
     float m_Meanval_sq;
 
     float *m_BesselApproxCoeff;
     float* ComputeFiberCorrelation();
     float Bessel(float x);
     void GenerateParticleGrid();
 
     int m_bD;
     float m_ParticleWidth;
     float m_ParticleLength;
     float m_ParticleWeight;
   };
 }
 #endif