diff --git a/CMakeLists.txt b/CMakeLists.txt
index 40bcc6f95..9dec1c90b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -109,26 +109,16 @@ function(add_c_compiler_flag_if_supported VARIABLE FLAG)
   endif()
 endfunction()
 
-function(add_cxx_compiler_flag_if_supported VARIABLE FLAG)
-  if(ARGC GREATER 2)
-    set(CHECKED_FLAG "${ARGV2}")
-  else()
-    set(CHECKED_FLAG "${FLAG}")
-  endif()
-  string(REGEX REPLACE "[^A-Za-z0-9]" "_" CONFIG_VARIABLE "FLAG_SUPPORTED${CHECKED_FLAG}")
-  check_cxx_compiler_flag("${CHECKED_FLAG}" ${CONFIG_VARIABLE})
-  if(${CONFIG_VARIABLE})
-    if(${VARIABLE})
-      set("${VARIABLE}" "${${VARIABLE}};${FLAG}" PARENT_SCOPE)
-    else()
-      set("${VARIABLE}" "${FLAG}" PARENT_SCOPE)
-    endif()
-  endif()
-endfunction()
-
 if(NOT MSVC)
   if(CMAKE_VERSION VERSION_LESS 3.1 OR TARGET_OS STREQUAL "mac")
-    add_cxx_compiler_flag_if_supported(CMAKE_CXX_FLAGS -std=gnu++11)
+    check_cxx_compiler_flag(-std=gnu++11 FLAG_SUPPORTED_std_gnu__11)
+    if(FLAG_SUPPORTED_std_gnu__11)
+      if(CMAKE_CXX_FLAGS)
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")
+      else()
+        set(CMAKE_CXX_FLAGS -std=gnu++11)
+      endif()
+    endif()
   endif()
 
   # Protect the stack pointer.