diff --git a/cmake/FindCompilerCheck.cmake b/cmake/FindCompilerCheck.cmake
index 0c514d15..bdc9daba 100644
--- a/cmake/FindCompilerCheck.cmake
+++ b/cmake/FindCompilerCheck.cmake
@@ -34,8 +34,12 @@ elseif ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
  IF(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
   # Apple which does not has the official clang version number ... 
   string(REGEX REPLACE ".*LLVM ([2-5]\\.[0-9]).*" "\\1" compiler_version ${_compiler_output})
+  # but this does not work if clang is not from Apple (compiled manually on the mac)
+  if (NOT ${compiler_version})
+  string(REGEX REPLACE ".* version ([2-5]\\.[0-9]).*" "\\1" compiler_version ${_compiler_output})
+  endif()
  else()
-  string(REGEX REPLACE ".*([2-5]\\.[0-9]).*" "\\1" compiler_version ${_compiler_output})
+  string(REGEX REPLACE ".* version ([2-5]\\.[0-9]).*" "\\1" compiler_version ${_compiler_output})
  endif()
  #message(STATUS "Compiler --version output = ${_compiler_output}")
  message(STATUS "Compiler version = ${compiler_version}")