diff --git a/indra/cmake/Variables.cmake b/indra/cmake/Variables.cmake
index faca12c347c65a43e14ca0593c9237bfcd2ae3e8..76d92d7a48c3eb7e114348b6026347b6595f0ce5 100755
--- a/indra/cmake/Variables.cmake
+++ b/indra/cmake/Variables.cmake
@@ -138,7 +138,7 @@ if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
   set(CMAKE_XCODE_ATTRIBUTE_GCC_VERSION "com.apple.compilers.llvm.clang.1_0")
   set(CMAKE_XCODE_ATTRIBUTE_GCC_OPTIMIZATION_LEVEL 3)
   set(CMAKE_XCODE_ATTRIBUTE_GCC_STRICT_ALIASING NO)
-  set(CMAKE_XCODE_ATTRIBUTE_GCC_FAST_MATH YES)
+  set(CMAKE_XCODE_ATTRIBUTE_GCC_FAST_MATH NO)
   set(CMAKE_XCODE_ATTRIBUTE_CLANG_X86_VECTOR_INSTRUCTIONS ssse3)
   set(CMAKE_XCODE_ATTRIBUTE_CLANG_CXX_LIBRARY "libstdc++")
   set(CMAKE_XCODE_ATTRIBUTE_DEBUG_INFORMATION_FORMAT dwarf-with-dsym)