diff --git a/CMakeLists.txt b/CMakeLists.txt
index a51dbc68d5..cef81d8d45 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -112,7 +112,7 @@ set(CMAKE_PREFIX_PATH ${CMAKE_PREFIX_PATH} ${QT_CMAKE_PREFIX_PATH})
 
 if (APPLE)
   
-  option(OSX_SDK "OS X SDK version to look for beside Xcode" 10.9)
+  option(OSX_SDK "OS X SDK version to look for inside Xcode bundle or at OSX_SDK_PATH" 10.9)
   
   # set our OS X deployment target
   set(CMAKE_OSX_DEPLOYMENT_TARGET 10.8)