diff --git a/CMake/AddCXXCompilerFlag.cmake b/CMake/AddCXXCompilerFlag.cmake
index ef3dfaaf..6fb615a1 100644
--- a/CMake/AddCXXCompilerFlag.cmake
+++ b/CMake/AddCXXCompilerFlag.cmake
@@ -29,20 +29,20 @@ endfunction(mangle_compiler_flag)
 
 function(add_cxx_compiler_flag FLAG)
   string(REPLACE "-Wno-" "-W" MAIN_FLAG ${FLAG})
-  mangle_compiler_flag("${MAIN_FLAG}" MANGLED_FLAG)
+  mangle_compiler_flag("${MAIN_FLAG}" MANGLED_FLAG_NAME)
   if (DEFINED CMAKE_REQUIRED_FLAGS)
     set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
     set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}")
   else()
     set(CMAKE_REQUIRED_FLAGS "${FLAG}")
   endif()
-  check_cxx_compiler_flag("${MAIN_FLAG}" ${MANGLED_FLAG})
+  check_cxx_compiler_flag("${MAIN_FLAG}" ${MANGLED_FLAG_NAME})
   if (DEFINED OLD_CMAKE_REQUIRED_FLAGS)
     set(CMAKE_REQUIRED_FLAGS "${OLD_CMAKE_REQUIRED_FLAGS}")
   else()
     unset(CMAKE_REQUIRED_FLAGS)
   endif()
-  if (MANGLED_FLAG)
+  if (${MANGLED_FLAG_NAME})
     set(VARIANT ${ARGV1})
     if (ARGV1)
       string(TOUPPER "_${VARIANT}" VARIANT)
@@ -53,12 +53,12 @@ endfunction()
 
 function(add_required_cxx_compiler_flag FLAG)
   string(REPLACE "-Wno-" "-W" MAIN_FLAG ${FLAG})
-  mangle_compiler_flag("${MAIN_FLAG}" MANGLED_FLAG)
+  mangle_compiler_flag("${MAIN_FLAG}" MANGLED_FLAG_NAME)
   set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}")
-  check_cxx_compiler_flag("${MAIN_FLAG}" ${MANGLED_FLAG})
+  check_cxx_compiler_flag("${MAIN_FLAG}" ${MANGLED_FLAG_NAME})
   set(CMAKE_REQUIRED_FLAGS "${OLD_CMAKE_REQUIRED_FLAGS}")
-  if (MANGLED_FLAG)
+  if (${MANGLED_FLAG_NAME})
     set(VARIANT ${ARGV1})
     if (ARGV1)
       string(TOUPPER "_${VARIANT}" VARIANT)