diff --git a/CMakeLists.txt b/CMakeLists.txt
index cc0d186d7..6548dadcd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -12,10 +12,12 @@ set (HAVE_CMAKE true)
 project (task)
 set (PROJECT_VERSION "2.4.1")
 
+set (CMAKE_CXX_FLAGS "-std=c++11")
 if (${CMAKE_SYSTEM_NAME} MATCHES "Linux")
   set (LINUX true)
 elseif (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
   set (DARWIN true)
+  set (CMAKE_CXX_FLAGS "-std=c++11 -stdlib=libc++")
 elseif (${CMAKE_SYSTEM_NAME} MATCHES "kFreeBSD")
   set (KFREEBSD true)
 elseif (${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD")