diff --git a/CMakeLists.txt b/CMakeLists.txt
index eeb924a1bcafd589ac5e598c0cff7986cae3c0aa..9a729ed80753201a3a425e2b968332132e42196c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -147,9 +147,9 @@ endfunction()
 if (CMAKE_COMPILER_IS_GNUCXX)
   get_compiler_version(_GCC_VERSION)
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
-  if (APPLE AND NOT GCC_VERSION MATCHES "42")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility=hidden")
-  endif()
+  if (APPLE AND NOT _GCC_VERSION MATCHES "42")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility=hidden")
+  endif()
 endif()
 
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY)