diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index c2fd8d7..2e86014 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -399,6 +399,7 @@
   DefineTypeWidth("__SIZE_WIDTH__", TI.getSizeType(), TI, Buf);
   DefineType("__WCHAR_TYPE__", TI.getWCharType(), Buf);
   DefineType("__WINT_TYPE__", TI.getWIntType(), Buf);
+  DefineTypeWidth("__WINT_WIDTH__", TI.getWIntType(), TI, Buf);
 
   DefineFloatMacros(Buf, "FLT", &TI.getFloatFormat());
   DefineFloatMacros(Buf, "DBL", &TI.getDoubleFormat());