diff --git a/lib/Frontend/InitPreprocessor.cpp b/lib/Frontend/InitPreprocessor.cpp
index 1ad9d5c..8f4cdbc 100644
--- a/lib/Frontend/InitPreprocessor.cpp
+++ b/lib/Frontend/InitPreprocessor.cpp
@@ -280,6 +280,9 @@
   if (LangOpts.ObjC2)
     DefineBuiltinMacro(Buf, "OBJC_NEW_PROPERTIES");
 
+  if (LangOpts.ObjCSenderDispatch)
+    DefineBuiltinMacro(Buf, "__OBJC_SENDER_AWARE_DISPATCH__");
+
   if (LangOpts.PascalStrings)
     DefineBuiltinMacro(Buf, "__PASCAL_STRINGS__");