diff --git a/IlmBase/CMakeLists.txt b/IlmBase/CMakeLists.txt
index e13c768..95942c8 100644
--- a/IlmBase/CMakeLists.txt
+++ b/IlmBase/CMakeLists.txt
@@ -110,7 +110,7 @@ ENDIF ()
 
 IF (OPENEXR_FORCE_CXX03)
   FILE ( APPEND  ${ILMBASE_TMP_CONFIG} "#define ILMBASE_FORCE_CXX03 1\n" )
-ELSEIF (NOT WIN32)
+ELSEIF (NOT WIN32 AND NOT APPLE)
   # really only care about c++11 right now for the threading bits, but this can be changed to 14
   # when needed...
   # Note that the __cplusplus check is not valid under MSVC