--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -303,16 +303,17 @@
 ########################################################################
 include(GrMiscUtils) #compiler flag check
 
-if(CMAKE_COMPILER_IS_GNUCXX AND NOT WIN32)
-    #http://gcc.gnu.org/wiki/Visibility
-    GR_ADD_CXX_COMPILER_FLAG_IF_AVAILABLE(-fvisibility=hidden HAVE_VISIBILITY_HIDDEN)
-endif()
-
-if(CMAKE_COMPILER_IS_GNUCXX)
+if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR
+   CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+    if(NOT WIN32)
+        #http://gcc.gnu.org/wiki/Visibility
+        GR_ADD_CXX_COMPILER_FLAG_IF_AVAILABLE(-fvisibility=hidden HAVE_VISIBILITY_HIDDEN)
+    endif(NOT WIN32)
     GR_ADD_CXX_COMPILER_FLAG_IF_AVAILABLE(-Wsign-compare HAVE_WARN_SIGN_COMPARE)
     GR_ADD_CXX_COMPILER_FLAG_IF_AVAILABLE(-Wall HAVE_WARN_ALL)
     GR_ADD_CXX_COMPILER_FLAG_IF_AVAILABLE(-Wno-uninitialized HAVE_WARN_NO_UNINITIALIZED)
-endif(CMAKE_COMPILER_IS_GNUCXX)
+endif(CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR
+      CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
 
 if(MSVC)
     include_directories(${CMAKE_SOURCE_DIR}/cmake/msvc) #missing headers