diff --git a/Modules/IGT/Testing/mitkPolhemusTrackingDeviceHardwareTest.cpp b/Modules/IGT/Testing/mitkPolhemusTrackingDeviceHardwareTest.cpp
index 5538870444..1a8328106c 100644
--- a/Modules/IGT/Testing/mitkPolhemusTrackingDeviceHardwareTest.cpp
+++ b/Modules/IGT/Testing/mitkPolhemusTrackingDeviceHardwareTest.cpp
@@ -1,65 +1,65 @@
 /*===================================================================
 
 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.
 
 ===================================================================*/
 
 #include "mitkPolhemusInterface.h"
 #include "mitkTestingMacros.h"
 #include "mitkStandardFileLocations.h"
 #include <mitkIGTConfig.h>
 
 // Testing
 #include "mitkTestingMacros.h"
 #include "mitkTestFixture.h"
 
 class mitkPolhemusTrackingDeviceHardwareTestSuite : public mitk::TestFixture
 {
   CPPUNIT_TEST_SUITE(mitkPolhemusTrackingDeviceHardwareTestSuite);
   // Test the append method
   MITK_TEST(testInterface);
   CPPUNIT_TEST_SUITE_END();
 
 
 public:
   void setUp() override
   {
 
   }
   void tearDown() override
   {
 
   }
 
   void testInterface()
   {
     mitk::PolhemusInterface::Pointer myInterface = mitk::PolhemusInterface::New();
     CPPUNIT_ASSERT_MESSAGE("Testing connection.", myInterface->Connect());
     CPPUNIT_ASSERT_MESSAGE("Start tracking.", myInterface->StartTracking());
 
     CPPUNIT_ASSERT_MESSAGE("Tracking 20 frames ...", true);
     for (int i = 0; i < 20; i++)
     {
       std::vector<mitk::PolhemusInterface::trackingData> lastFrame = myInterface->GetLastFrame();
       MITK_INFO << "Frame " << i;
-      for (int j = 0; j < lastFrame.size(); j++)
+      for (size_t j = 0; j < lastFrame.size(); j++)
       {
         MITK_INFO << "[" << j << "]" << " Pos:" << lastFrame.at(j).pos << " Rot:" << lastFrame.at(j).rot;
       }
     }
 
   }
 
 };
 
 MITK_TEST_SUITE_REGISTRATION(mitkPolhemusTrackingDeviceHardware)