diff --git a/Core/Code/Testing/mitkImageVtkMapper2DTransferFunctionTest.cpp b/Core/Code/Testing/mitkImageVtkMapper2DTransferFunctionTest.cpp
index 7366a1845e..4c854deda8 100644
--- a/Core/Code/Testing/mitkImageVtkMapper2DTransferFunctionTest.cpp
+++ b/Core/Code/Testing/mitkImageVtkMapper2DTransferFunctionTest.cpp
@@ -1,83 +1,86 @@
 /*===================================================================
 
 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.
 
 ===================================================================*/
 
 //MITK
 #include "mitkTestingMacros.h"
 #include "mitkRenderingTestHelper.h"
 
 //VTK
 #include <vtkRegressionTestImage.h>
 #include <mitkTransferFunctionProperty.h>
 #include <mitkTransferFunction.h>
 
 
 int mitkImageVtkMapper2DTransferFunctionTest(int argc, char* argv[])
 {
     // load all arguments into a datastorage, take last argument as reference rendering
     // setup a renderwindow of fixed size X*Y
     // render the datastorage
     // compare rendering to reference image
     MITK_TEST_BEGIN("mitkImageVtkMapper2DTransferFunctionTest")
 
     // enough parameters?
     if ( argc < 2 )
     {
         MITK_TEST_OUTPUT( << "Usage: " << std::string(*argv) << " [file1 file2 ...] outputfile" )
                 MITK_TEST_OUTPUT( << "Will render a central axial slice of all given files into outputfile" )
                 exit( EXIT_SUCCESS );
     }
     mitkRenderingTestHelper renderingHelper(640, 480, argc, argv);
 
     //define an arbitrary colortransferfunction
     vtkSmartPointer<vtkColorTransferFunction> colorTransferFunction = vtkSmartPointer<vtkColorTransferFunction>::New();
     colorTransferFunction->SetColorSpaceToRGB();
     colorTransferFunction->AddRGBPoint(0.0, 1, 0, 0); //black = red
     colorTransferFunction->AddRGBPoint(127.5, 0, 1, 0); //grey = green
     colorTransferFunction->AddRGBPoint(255.0, 0, 0, 1); //white = blue
     mitk::TransferFunction::Pointer transferFucntion = mitk::TransferFunction::New();
     transferFucntion->SetColorTransferFunction( colorTransferFunction );
 
     //set the property for the image
     renderingHelper.SetImageProperty("Image Rendering.Transfer Function", mitk::TransferFunctionProperty::New(transferFucntion));
 
     renderingHelper.Render();
 
     //use this to generate a reference screenshot or save the file:
     bool generateReferenceScreenshot = false;
     if(generateReferenceScreenshot)
     {
         renderingHelper.SaveAsPNG("/home/kilgus/Pictures/RenderingTestData/output.png");
     }
 
+    renderingHelper.PrepareRender();
     //### Usage of vtkRegressionTestImage:
     //vtkRegressionTestImage( vtkRenderWindow )
     //Set a vtkRenderWindow containing the desired scene.
     //vtkRegressionTestImage automatically searches in argc and argv[]
     //for a path a valid image with -V. If the test failed with the
     //first image (foo.png) check if there are images of the form
     //foo_N.png (where N=1,2,3...) and compare against them.
-    renderingHelper.PrepareRender();
-    int retVal = vtkRegressionTestImage( renderingHelper.GetVtkRenderWindow() );
+    //Default tolerance for rendering tests is 10 (set by VTK).
+    //For this case, small artifacts in Windows occur and boundaries of the fonts,
+    //thus we double the default tolerance threshold and set it to 20.
+    int retVal = vtkTesting::Test(argc, argv, renderingHelper.GetVtkRenderWindow(), 20 );
 
     //retVal meanings: (see VTK/Rendering/vtkTesting.h)
     //0 = test failed
     //1 = test passed
     //2 = test not run
     //3 = something with vtkInteraction
     MITK_TEST_CONDITION( retVal == 1, "VTK test result positive" );
 
     MITK_TEST_END();
 }