diff --git a/Modules/PhotoacousticsAlgorithms/files.cmake b/Modules/PhotoacousticsAlgorithms/files.cmake
index ac29b12402..b3fdaff026 100644
--- a/Modules/PhotoacousticsAlgorithms/files.cmake
+++ b/Modules/PhotoacousticsAlgorithms/files.cmake
@@ -1,20 +1,25 @@
 file(GLOB_RECURSE H_FILES RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" "${CMAKE_CURRENT_SOURCE_DIR}/include/*")
 
 set(CPP_FILES
   source/mitkPhotoacousticImage.cpp
   source/mitkPhotoacousticBeamformingFilter.cpp
-  source/OpenCLFilter/mitkPhotoacousticOCLBeamformingFilter.cpp
   source/OpenCLFilter/mitkPhotoacousticBModeFilter.cpp
-  source/OpenCLFilter/mitkPhotoacousticOCLUsedLinesCalculation.cpp
-  source/OpenCLFilter/mitkPhotoacousticOCLDelayCalculation.cpp
 )
 
+IF(MITK_USE_OpenCL)
+list(APPEND CPP_FILES
+    source/OpenCLFilter/mitkPhotoacousticOCLBeamformingFilter.cpp
+    source/OpenCLFilter/mitkPhotoacousticOCLUsedLinesCalculation.cpp
+    source/OpenCLFilter/mitkPhotoacousticOCLDelayCalculation.cpp
+)
+ENDIF(MITK_USE_OpenCL)
+
 set(RESOURCE_FILES
   BModeAbs.cl
   BModeAbsLog.cl
   UsedLinesCalculation.cl
   DelayCalculation.cl
   DMAS.cl
   DAS.cl
   sDMAS.cl
 )
diff --git a/Modules/PhotoacousticsAlgorithms/include/OpenCLFilter/mitkPhotoacousticOCLBeamformingFilter.h b/Modules/PhotoacousticsAlgorithms/include/OpenCLFilter/mitkPhotoacousticOCLBeamformingFilter.h
index 885223739d..78ced9688a 100644
--- a/Modules/PhotoacousticsAlgorithms/include/OpenCLFilter/mitkPhotoacousticOCLBeamformingFilter.h
+++ b/Modules/PhotoacousticsAlgorithms/include/OpenCLFilter/mitkPhotoacousticOCLBeamformingFilter.h
@@ -1,152 +1,154 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #ifndef _MITKPHOTOACOUSTICSOCLBEAMFORMER_H_
 #define _MITKPHOTOACOUSTICSOCLBEAMFORMER_H_
 
 #include <itkObject.h>
 
 #if defined(PHOTOACOUSTICS_USE_GPU) || DOXYGEN
 
 #include "mitkOclDataSetToDataSetFilter.h"
 
 #include "mitkPhotoacousticOCLDelayCalculation.h"
 #include "mitkPhotoacousticOCLUsedLinesCalculation.h"
 #include "mitkPhotoacousticBeamformingSettings.h"
 
 #include <chrono>
 
 namespace mitk
 {
   /*!
   * \brief Class implementing a mitk::OclDataSetToDataSetFilter for beamforming on GPU
   *
   *  The class must be given a configuration class instance of mitk::BeamformingSettings for beamforming parameters through mitk::PhotoacousticOCLBeamformingFilter::SetConfig(BeamformingSettings settings)
   *  Additional configuration of the apodisation function is needed.
   */
 
 class PhotoacousticOCLBeamformingFilter : public OclDataSetToDataSetFilter, public itk::Object
 {
 
 public:
   mitkClassMacroItkParent(PhotoacousticOCLBeamformingFilter, itk::Object);
   itkNewMacro(Self);
 
   /**
   * @brief SetInput Set the input data through an image. Arbitrary images are supported
   */
   void SetInput(Image::Pointer image);
   /**
   *  brief SetInput Manually set the input data while providing 3 dimensions and memory size of the input data (Bytes per element).
   */
   void SetInput(void* data, unsigned int* dimensions, unsigned int BpE);
   /**
   * @brief GetOutput Get a pointer to the processed data. The standard datatype is float.
   */
   void* GetOutput();
 
   /**
   * @brief GetOutputAsImage Returns an mitk::Image constructed from the processed data
   */
   mitk::Image::Pointer GetOutputAsImage();
 
   /** \brief Update the filter */
   void Update();
 
   /** \brief Set the Apodisation function to apply when beamforming */
   void SetApodisation(float* apodisation, unsigned short apodArraySize)
   {
     m_ApodArraySize = apodArraySize;
     m_Apodisation = apodisation;
   }
 
   /** \brief Set beamforming settings to use when beamforming */
   void SetConfig(BeamformingSettings settings)
   {
     m_ConfOld = m_Conf;
     m_Conf = settings;
   }
 
 protected:
 
   PhotoacousticOCLBeamformingFilter();
   virtual ~PhotoacousticOCLBeamformingFilter();
 
   /** \brief Initialize the filter */
   bool Initialize();
 
   /** \brief Updated the used data for beamforming depending on whether the configuration has significantly changed */
   void UpdateDataBuffers();
 
   /** \brief Execute the filter */
   void Execute();
 
   mitk::PixelType GetOutputType()
   {
     return mitk::MakeScalarPixelType<float>();
   }
 
   int GetBytesPerElem()
   {
     return sizeof(float);
   }
 
   virtual us::Module* GetModule();
 
 private:
   /** The OpenCL kernel for the filter */
   cl_kernel m_PixelCalculation;
 
   unsigned int m_OutputDim[3];
 
   float* m_Apodisation;
   unsigned short m_ApodArraySize;
 
   unsigned short m_PAImage;
 
   BeamformingSettings m_Conf;
   BeamformingSettings m_ConfOld;
 
   mitk::Image::Pointer m_InputImage;
 
   size_t m_ChunkSize[3];
 
   mitk::OCLUsedLinesCalculation::Pointer m_UsedLinesCalculation;
   mitk::OCLDelayCalculation::Pointer m_DelayCalculation;
 
   cl_mem m_ApodizationBuffer;
   cl_mem m_MemoryLocationsBuffer;
   cl_mem m_DelaysBuffer;
   cl_mem m_UsedLinesBuffer;
 };
 }
 #else
-class PhotoacousticOCLBeamformingFilter : public itk::Object
+namespace mitk
 {
-public:
-  mitkClassMacroItkParent(mitk::PhotoacousticOCLBeamformingFilter, itk::Object);
-  itkNewMacro(Self);
+  class PhotoacousticOCLBeamformingFilter : public itk::Object
+  {
+  public:
+    mitkClassMacroItkParent(mitk::PhotoacousticOCLBeamformingFilter, itk::Object);
+    itkNewMacro(Self);
 
-protected:
-  /** Constructor */
-  PhotoacousticOCLBeamformingFilter() {}
+  protected:
+    /** Constructor */
+    PhotoacousticOCLBeamformingFilter() {}
 
-  /** Destructor */
-  virtual ~PhotoacousticOCLBeamformingFilter() {}
-};
+    /** Destructor */
+    virtual ~PhotoacousticOCLBeamformingFilter() {}
+  };
 }
 #endif
 #endif