diff --git a/indra/cmake/Variables.cmake b/indra/cmake/Variables.cmake
index 74666be9cbc93420bb4ce35056628dd82d2ef070..969726e6e11e172826059aed2c6bc402720b4394 100644
--- a/indra/cmake/Variables.cmake
+++ b/indra/cmake/Variables.cmake
@@ -149,6 +149,7 @@ if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
   set(CMAKE_XCODE_ATTRIBUTE_GCC_STRICT_ALIASING NO)
   set(CMAKE_XCODE_ATTRIBUTE_GCC_FAST_MATH NO)
   set(CMAKE_XCODE_ATTRIBUTE_CLANG_X86_VECTOR_INSTRUCTIONS ssse3)
+  message(WARNING "Change Variables.cmake to specify libc++ when updating with p64 3p libraries")
   set(CMAKE_XCODE_ATTRIBUTE_CLANG_CXX_LIBRARY "libstdc++")
   set(CMAKE_XCODE_ATTRIBUTE_DEBUG_INFORMATION_FORMAT dwarf-with-dsym)