if(NOT GNURADIO_RUNTIME_FOUND)
  INCLUDE(FindPkgConfig)
  PKG_CHECK_MODULES(PC_GNURADIO_RUNTIME gnuradio-runtime)

  # look for include files
  FIND_PATH(
    GNURADIO_RUNTIME_INCLUDE_DIRS
    NAMES gnuradio/top_block.h
    HINTS $ENV{GNURADIO_RUNTIME_DIR}/include
          ${PC_GNURADIO_RUNTIME_INCLUDE_DIRS}
          ${CMAKE_INSTALL_PREFIX}/include
    PATHS /usr/local/include
          /usr/include
    )

  if(NOT PC_GNURADIO_RUNTIME_FOUND)
   set(PC_GNURADIO_RUNTIME_LIBRARIES gnuradio-runtime)
  endif(NOT PC_GNURADIO_RUNTIME_FOUND)

  foreach(libname ${PC_GNURADIO_RUNTIME_LIBRARIES})
    # look for libs
    FIND_LIBRARY(
      GNURADIO_RUNTIME_LIBRARIES_${libname}
      NAMES ${libname}
      HINTS $ENV{GNURADIO_RUNTIME_DIR}/lib
            ${PC_GNURADIO_RUNTIME_LIBDIR}
            ${CMAKE_INSTALL_PREFIX}/lib/
            ${CMAKE_INSTALL_PREFIX}/lib64/
      PATHS /usr/local/lib
            /usr/local/lib64
            /usr/lib
            /usr/lib64
      )
    list(APPEND GNURADIO_RUNTIME_LIBRARIES ${GNURADIO_RUNTIME_LIBRARIES_${libname}})
  endforeach(libname)

  set (GNURADIO_RUNTIME_LIBRARIES ${GNURADIO_RUNTIME_LIBRARIES} CACHE FILEPATH "gnuradio-runtime libraries")

  if (GNURADIO_RUNTIME_INCLUDE_DIRS AND GNURADIO_RUNTIME_LIBRARIES)
    set(GNURADIO_RUNTIME_FOUND TRUE CACHE INTERNAL "gnuradio-runtime found")
  else (GNURADIO_RUNTIME_INCLUDE_DIRS AND GNURADIO_RUNTIME_LIBRARIES)
    set(GNURADIO_RUNTIME_FOUND FALSE CACHE INTERNAL "gnuradio-runtime found")
  endif(GNURADIO_RUNTIME_INCLUDE_DIRS AND GNURADIO_RUNTIME_LIBRARIES)

  INCLUDE(FindPackageHandleStandardArgs)
  # do not check GNURADIO_RUNTIME_INCLUDE_DIRS, is not set when default include path us used.
  FIND_PACKAGE_HANDLE_STANDARD_ARGS(GNURADIO_RUNTIME DEFAULT_MSG GNURADIO_RUNTIME_LIBRARIES)

  MARK_AS_ADVANCED(GNURADIO_RUNTIME_LIBRARIES GNURADIO_RUNTIME_INCLUDE_DIRS)

endif(NOT GNURADIO_RUNTIME_FOUND)