diff --git a/CMakeExternals/OpenCV.cmake b/CMakeExternals/OpenCV.cmake
index 8190bc8a10..e7da362cb2 100644
--- a/CMakeExternals/OpenCV.cmake
+++ b/CMakeExternals/OpenCV.cmake
@@ -1,100 +1,104 @@
 #-----------------------------------------------------------------------------
 # OpenCV
 #-----------------------------------------------------------------------------
 
 if(MITK_USE_OpenCV)
 
   # Sanity checks
   if(DEFINED OpenCV_DIR AND NOT EXISTS ${OpenCV_DIR})
     message(FATAL_ERROR "OpenCV_DIR variable is defined but corresponds to non-existing directory")
   endif()
 
   set(proj OpenCV)
   set(proj_DEPENDENCIES)
   set(OpenCV_DEPENDS ${proj})
 
   if(NOT DEFINED OpenCV_DIR)
 
     set(additional_cmake_args
       -DBUILD_opencv_java:BOOL=OFF
     )
 
     if(MITK_USE_Python)
       #message(STATUS "PYTHON_EXECUTABLE: ${PYTHON_EXECUTABLE}")
       #message(STATUS "PYTHON_DEBUG_LIBRARY: ${PYTHON_DEBUG_LIBRARY}")
       #message(STATUS "PYTHON_INCLUDE_DIR: ${PYTHON_INCLUDE_DIR}")
       #message(STATUS "PYTHON_LIBRARY: ${PYTHON_LIBRARY}")
       list(APPEND additional_cmake_args
          -DBUILD_opencv_python:BOOL=ON
          -DBUILD_NEW_PYTHON_SUPPORT:BOOL=ON
          -DPYTHON_DEBUG_LIBRARY:FILEPATH=${PYTHON_DEBUG_LIBRARY}
          -DPYTHON_EXECUTABLE:FILEPATH=${PYTHON_EXECUTABLE}
          -DPYTHON_INCLUDE_DIR:PATH=${PYTHON_INCLUDE_DIR}
          -DPYTHON_INCLUDE_DIR2:PATH=${PYTHON_INCLUDE_DIR2}
          -DPYTHON_LIBRARY:FILEPATH=${PYTHON_LIBRARY}
 
          #-DPYTHON_LIBRARIES=${PYTHON_LIBRARY}
          #-DPYTHON_DEBUG_LIBRARIES=${PYTHON_DEBUG_LIBRARIES}
           )
       if(NOT MITK_USE_SYSTEM_PYTHON)
         list(APPEND proj_DEPENDENCIES Python)
+        # set the python home to the correct python runtime.
+        # Else OpenCV will use default system paths during configuration.
+        if(WIN32)
+          set(ENV{PYTHONHOME} "${Python_BUILD_DIR}")
+        else()
+          set(ENV{PYTHONHOME} "${Python_DIR}")
+        endif()
       endif()
       # use the numpy build within mitk
       if(MITK_USE_NUMPY)
         list(APPEND proj_DEPENDENCIES Numpy)
-        list(APPEND additional_cmake_args
-          -DPYTHON_NUMPY_INCLUDE_DIR:PATH=${Numpy_DIR}/numpy/core/include
-            )
       endif()
     else()
       list(APPEND additional_cmake_args
          -DBUILD_opencv_python:BOOL=OFF
          -DBUILD_NEW_PYTHON_SUPPORT:BOOL=OFF
           )
     endif()
 
     # 12-05-02, muellerm, added QT usage by OpenCV if QT is used in MITK
     # 12-09-11, muellerm, removed automatic usage again, since this will struggle with the MITK Qt application object
     if(MITK_USE_QT)
       list(APPEND additional_cmake_args
            -DWITH_QT:BOOL=OFF
            -DWITH_QT_OPENGL:BOOL=OFF
            -DQT_QMAKE_EXECUTABLE:FILEPATH=${QT_QMAKE_EXECUTABLE}
           )
     endif()
 
     set(OpenCV_PATCH_COMMAND ${CMAKE_COMMAND} -DTEMPLATE_FILE:FILEPATH=${MITK_SOURCE_DIR}/CMakeExternals/EmptyFileForPatching.dummy -P ${MITK_SOURCE_DIR}/CMakeExternals/PatchOpenCV-2.4.8.2.cmake)
 
 
     set(opencv_url ${MITK_THIRDPARTY_DOWNLOAD_PREFIX_URL}/OpenCV-2.4.8.2.tar.gz)
     set(opencv_url_md5 07fa7c1d225ea7fe8eeb1270a6b00e69)
 
     ExternalProject_Add(${proj}
       SOURCE_DIR ${CMAKE_BINARY_DIR}/${proj}-src
       BINARY_DIR ${proj}-build
       PREFIX ${proj}-cmake
       URL ${opencv_url}
       URL_MD5 ${opencv_url_md5}
       INSTALL_COMMAND ""
       PATCH_COMMAND ${OpenCV_PATCH_COMMAND}
       CMAKE_GENERATOR ${gen}
       CMAKE_ARGS
         ${ep_common_args}
         -DBUILD_DOCS:BOOL=OFF
         -DBUILD_TESTS:BOOL=OFF
         -DBUILD_EXAMPLES:BOOL=OFF
         -DBUILD_DOXYGEN_DOCS:BOOL=OFF
         -DWITH_CUDA:BOOL=ON
         ${additional_cmake_args}
       DEPENDS ${proj_DEPENDENCIES}
     )
 
     set(OpenCV_DIR ${CMAKE_CURRENT_BINARY_DIR}/${proj}-build)
 
   else()
 
     mitkMacroEmptyExternalProject(${proj} "${proj_DEPENDENCIES}")
 
   endif()
 
 endif()