diff --git a/clang/include/clang/Basic/TokenKinds.def b/clang/include/clang/Basic/TokenKinds.def
index c50b31d37409..b16b82854b1c 100644
--- a/clang/include/clang/Basic/TokenKinds.def
+++ b/clang/include/clang/Basic/TokenKinds.def
@@ -220,7 +220,7 @@ KEYWORD(unsigned                    , KEYALL)
 KEYWORD(void                        , KEYALL)
 KEYWORD(volatile                    , KEYALL)
 KEYWORD(while                       , KEYALL)
-KEYWORD(_Bool                       , KEYALL)
+KEYWORD(_Bool                       , KEYNOMS)
 KEYWORD(_Complex                    , KEYALL)
 KEYWORD(_Imaginary                  , KEYALL)
 KEYWORD(__func__                    , KEYALL)
diff --git a/clang/lib/Basic/IdentifierTable.cpp b/clang/lib/Basic/IdentifierTable.cpp
index ed0de8c4af09..8993e6713fbe 100644
--- a/clang/lib/Basic/IdentifierTable.cpp
+++ b/clang/lib/Basic/IdentifierTable.cpp
@@ -70,7 +70,8 @@ namespace {
     KEYGNU = 16,
     KEYMS = 32,
     BOOLSUPPORT = 64,
-    KEYALTIVEC = 128
+    KEYALTIVEC = 128,
+    KEYNOMS = 256
   };
 }
 
@@ -94,6 +95,7 @@ static void AddKeyword(llvm::StringRef Keyword,
   else if (LangOpts.Microsoft && (Flags & KEYMS)) AddResult = 1;
   else if (LangOpts.Bool && (Flags & BOOLSUPPORT)) AddResult = 2;
   else if (LangOpts.AltiVec && (Flags & KEYALTIVEC)) AddResult = 2;
+  else if (!LangOpts.Microsoft && (Flags & KEYNOMS)) AddResult = 2;
 
   // Don't add this keyword if disabled in this language.
   if (AddResult == 0) return;