Index: include/clang/Basic/TokenKinds.def
===================================================================
--- include/clang/Basic/TokenKinds.def
+++ include/clang/Basic/TokenKinds.def
@@ -10,7 +10,8 @@
 // This file defines the TokenKind database.  This includes normal tokens like
 // tok::ampamp (corresponding to the && token) as well as keywords for various
 // languages.  Users of this file must optionally #define the TOK, KEYWORD,
-// CXX11_KEYWORD, ALIAS, or PPKEYWORD macros to make use of this file.
+// CXX11_KEYWORD, CONCEPTS_KEYWORD, ALIAS, or PPKEYWORD macros to make use of
+// this file.
 //
 //===----------------------------------------------------------------------===//
 
@@ -26,6 +27,9 @@
 #ifndef CXX11_KEYWORD
 #define CXX11_KEYWORD(X,Y) KEYWORD(X,KEYCXX11|(Y))
 #endif
+#ifndef CONCEPTS_KEYWORD
+#define CONCEPTS_KEYWORD(X) KEYWORD(X,KEYCONCEPTS)
+#endif
 #ifndef TYPE_TRAIT
 #define TYPE_TRAIT(N,I,K) KEYWORD(I,K)
 #endif
@@ -226,6 +230,8 @@
 //              implementation namespace
 //   KEYNOCXX - This is a keyword in every non-C++ dialect.
 //   KEYCXX11 - This is a C++ keyword introduced to C++ in C++11
+//   KEYCONCEPTS - This is a keyword if the C++ extensions for concepts
+//                 are enabled.
 //   KEYGNU   - This is a keyword if GNU extensions are enabled
 //   KEYMS    - This is a keyword if Microsoft extensions are enabled
 //   KEYNOMS18 - This is a keyword that must never be enabled under
@@ -344,6 +350,10 @@
 CXX11_KEYWORD(static_assert         , 0)
 CXX11_KEYWORD(thread_local          , 0)
 
+// C++ concepts TS keywords
+CONCEPTS_KEYWORD(concept)
+CONCEPTS_KEYWORD(requires)
+
 // GNU Extensions (in impl-reserved namespace)
 KEYWORD(_Decimal32                  , KEYALL)
 KEYWORD(_Decimal64                  , KEYALL)
@@ -738,6 +748,7 @@
 #undef TYPE_TRAIT_2
 #undef TYPE_TRAIT_1
 #undef TYPE_TRAIT
+#undef CONCEPTS_KEYWORD
 #undef CXX11_KEYWORD
 #undef KEYWORD
 #undef PUNCTUATOR
Index: lib/Basic/IdentifierTable.cpp
===================================================================
--- lib/Basic/IdentifierTable.cpp
+++ lib/Basic/IdentifierTable.cpp
@@ -109,7 +109,8 @@
     KEYNOOPENCL = 0x02000,
     WCHARSUPPORT = 0x04000,
     HALFSUPPORT = 0x08000,
-    KEYALL = (0xffff & ~KEYNOMS18 &
+    KEYCONCEPTS = 0x10000,
+    KEYALL = (0x1ffff & ~KEYNOMS18 &
               ~KEYNOOPENCL) // KEYNOMS18 and KEYNOOPENCL are used to exclude.
   };
 
@@ -143,6 +144,7 @@
   // We treat bridge casts as objective-C keywords so we can warn on them
   // in non-arc mode.
   if (LangOpts.ObjC2 && (Flags & KEYARC)) return KS_Enabled;
+  if (LangOpts.ConceptsTS && (Flags & KEYCONCEPTS)) return KS_Enabled;
   if (LangOpts.CPlusPlus && (Flags & KEYCXX11)) return KS_Future;
   return KS_Disabled;
 }
Index: test/Lexer/keywords_test.cpp
===================================================================
--- test/Lexer/keywords_test.cpp
+++ test/Lexer/keywords_test.cpp
@@ -1,10 +1,17 @@
 // RUN: %clang_cc1 -std=c++03 -fsyntax-only %s
 // RUN: %clang_cc1 -std=c++11 -DCXX11 -fsyntax-only %s
+// RUN: %clang_cc1 -std=c++14 -fconcepts-ts -DCXX11 -DCONCEPTS -fsyntax-only %s
 
 #define IS_KEYWORD(NAME) _Static_assert(!__is_identifier(NAME), #NAME)
 #define NOT_KEYWORD(NAME) _Static_assert(__is_identifier(NAME), #NAME)
 #define IS_TYPE(NAME) void is_##NAME##_type() { int f(NAME); }
 
+#ifdef CONCEPTS
+#define CONCEPTS_KEYWORD(NAME)  IS_KEYWORD(NAME)
+#else
+#define CONCEPTS_KEYWORD(NAME)  NOT_KEYWORD(NAME)
+#endif
+
 #ifdef CXX11
 #define CXX11_KEYWORD(NAME)  IS_KEYWORD(NAME)
 #define CXX11_TYPE(NAME)     IS_TYPE(NAME)
@@ -27,6 +34,10 @@
 CXX11_KEYWORD(static_assert);
 CXX11_KEYWORD(thread_local);
 
+// Concepts TS keywords
+CONCEPTS_KEYWORD(concept);
+CONCEPTS_KEYWORD(requires);
+
 // Clang extension
 IS_KEYWORD(__char16_t);
 IS_TYPE(__char16_t);