diff --git a/CMakeExternals/Numpy.cmake b/CMakeExternals/Numpy.cmake
index 67b9699acd..55ca78fbe3 100644
--- a/CMakeExternals/Numpy.cmake
+++ b/CMakeExternals/Numpy.cmake
@@ -1,123 +1,113 @@
 #-----------------------------------------------------------------------------
 # Numpy
 #-----------------------------------------------------------------------------
-if( NOT MITK_USE_SYSTEM_PYTHON )
+if( MITK_USE_Python AND NOT MITK_USE_SYSTEM_PYTHON )
   # Sanity checks
   if(DEFINED Numpy_DIR AND NOT EXISTS ${Numpy_DIR})
     message(FATAL_ERROR "Numpy_DIR variable is defined but corresponds to non-existing directory")
   endif()
 
   if( NOT DEFINED Numpy_DIR )
     set(proj Numpy)
     set(${proj}_DEPENDENCIES Python)
     set(Numpy_DEPENDS ${proj})
 
     set(_numpy_env
         "
         set(ENV{F77} \"\")
         set(ENV{F90} \"\")
         set(ENV{FFLAGS} \"\")
         set(ENV{ATLAS} \"None\")
         set(ENV{BLAS} \"None\")
         set(ENV{LAPACK} \"None\")
         set(ENV{MKL} \"None\")
         ")
 
     set(_external_python_project ${CMAKE_BINARY_DIR}/mitkExternalPythonProject.cmake)
     file(WRITE ${_external_python_project}
         "
         ${_numpy_env}
         set(ENV{VS_UNICODE_OUTPUT} \"\")
         set(ENV{CC} \"${CMAKE_C_COMPILER} ${CMAKE_C_COMPILER_ARG1}\")
         set(ENV{CFLAGS} \"${CMAKE_C_FLAGS} ${CMAKE_C_FLAGS_RELEASE}\")
         set(ENV{CXX} \"${CMAKE_CXX_COMPILER} ${CMAKE_CXX_COMPILER_ARG1}\")
         set(ENV{CXXFLAGS} \"${CMAKE_CXX_FLAGS} ${CMAKE_CXX_FLAGS_RELEASE}\")
         set(ENV{LDFLAGS} \"${CMAKE_LINKER_FLAGS} ${CMAKE_LINKER_FLAGS_RELEASE}\")
 
         function(MITK_PYTHON_BUILD_STEP proj step)
            set(_command \${ARGN})
 
            message(\"Running \${proj} \${step}:${PYTHON_EXECUTABLE} \${_command}\")
 
            execute_process(
               COMMAND ${PYTHON_EXECUTABLE} \${_command}
               WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/\${proj}-src
               RESULT_VARIABLE result
               OUTPUT_VARIABLE output
               ERROR_VARIABLE error
            )
            set(output_file \"${CMAKE_BINARY_DIR}/\${proj}_\${step}_step_output.txt\")
            file(WRITE \${output_file} \${output})
 
            set(error_file \"${CMAKE_BINARY_DIR}/\${proj}_\${step}_step_error.txt\")
            file(WRITE \${error_file} \${error})
 
            if(NOT \${result} EQUAL 0)
              message(FATAL_ERROR \"Error in: \${proj}: \${error}\")
            endif()
          endfunction()
         ")
     # configure step
     set(_configure_step ${CMAKE_BINARY_DIR}/${proj}_configure_step.cmake)
     file(WRITE ${_configure_step}
        "include(\"${_external_python_project}\")
         file(WRITE \"${CMAKE_BINARY_DIR}/${proj}-src/site.cfg\" \"\")
         MITK_PYTHON_BUILD_STEP(${proj} configure setup.py config)
        ")
 
     # build step
     set(_build_step ${CMAKE_BINARY_DIR}/${proj}_build_step.cmake)
     file(WRITE ${_build_step}
        "include(\"${_external_python_project}\")
         MITK_PYTHON_BUILD_STEP(${proj} build setup.py build --fcompiler=none)
        ")
 
     # install step
-    set(NUMPY_CMAKE_INSTALL_DIR )
-    if(NOT MITK_USE_SYSTEM_PYTHON)
-      set(_install_dir ${Python_BUILD_DIR})
-      if(WIN32)
-        STRING(REPLACE "/" "\\\\" _install_dir ${Python_DIR})
-      endif()
-    else()
-      set(NUMPY_CMAKE_INSTALL_DIR INSTALL_DIR ${CMAKE_BINARY_DIR}/${proj}-install)
-      set(_install_dir "${CMAKE_BINARY_DIR}/${proj}-install")
-      if(WIN32)
-        STRING(REPLACE "/" "\\\\" _install_dir ${CMAKE_BINARY_DIR}/${proj}-install)
-      endif()
+    set(_install_dir ${Python_BUILD_DIR})
+    if(WIN32)
+      STRING(REPLACE "/" "\\\\" _install_dir ${Python_DIR})
     endif()
 
     set(_install_step ${CMAKE_BINARY_DIR}/${proj}_install_step.cmake)
     file(WRITE ${_install_step}
        "include(\"${_external_python_project}\")
         MITK_PYTHON_BUILD_STEP(${proj} install setup.py install --prefix=${_install_dir})
        ")
 
     set(Numpy_URL "https://dl.dropboxusercontent.com/u/8367205/ExternalProjects/numpy-1.4.1.tar.gz")
     set(Numpy_MD5 "5c7b5349dc3161763f7f366ceb96516b")
 
     ExternalProject_Add(${proj}
       URL ${Numpy_URL}
       URL_MD5 ${Numpy_MD5}
       SOURCE_DIR ${proj}-src
       PREFIX ${proj}-cmake
       BUILD_IN_SOURCE 1
-      ${NUMPY_CMAKE_INSTALL_DIR}
       CONFIGURE_COMMAND ${CMAKE_COMMAND} -P ${_configure_step}
       BUILD_COMMAND   ${CMAKE_COMMAND} -P ${_build_step}
       INSTALL_COMMAND ${CMAKE_COMMAND} -P ${_install_step}
 
       DEPENDS
         ${${proj}_DEPENDENCIES}
     )
 
     if(WIN32)
       set(Numpy_DIR ${_install_dir}/Lib/site-packages)
     else()
       set(Numpy_DIR ${_install_dir}/lib/python2.7/site-packages)
     endif()
   else()
     mitkMacroEmptyExternalProject(${proj} "${proj_DEPENDENCIES}")
   endif()
 endif()
 
diff --git a/CMakeExternals/OpenCV.cmake b/CMakeExternals/OpenCV.cmake
index 0eb9cd98d8..fab4c7c6f4 100644
--- a/CMakeExternals/OpenCV.cmake
+++ b/CMakeExternals/OpenCV.cmake
@@ -1,100 +1,95 @@
 #-----------------------------------------------------------------------------
 # 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)
+        list(APPEND proj_DEPENDENCIES Python Numpy)
         # export python home
         set(ENV{PYTHONHOME} "${Python_DIR}")
       endif()
-      # use the numpy build within mitk
-      if(MITK_USE_NUMPY)
-        list(APPEND proj_DEPENDENCIES Numpy)
-        )
-      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()