diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index 8457cc5ad6..1789e81b0a 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -307,7 +307,7 @@ class Preprocessor : public RefCountedBase<Preprocessor> {
   /// Macros - For each IdentifierInfo that was associated with a macro, we
   /// keep a mapping to the history of all macro definitions and #undefs in
   /// the reverse order (the latest one is in the head of the list).
-  llvm::DenseMap<IdentifierInfo*, MacroInfo*> Macros;
+  llvm::DenseMap<const IdentifierInfo*, MacroInfo*> Macros;
   friend class ASTReader;
   
   /// \brief Macros that we want to warn because they are not used at the end
@@ -520,7 +520,7 @@ public:
   /// representing the most recent macro definition. One can iterate over all
   /// previous macro definitions from it. This method should only be called for
   /// identifiers that hadMacroDefinition().
-  MacroInfo *getMacroInfoHistory(IdentifierInfo *II) const;
+  MacroInfo *getMacroInfoHistory(const IdentifierInfo *II) const;
 
   /// \brief Specify a macro for this identifier.
   void setMacroInfo(IdentifierInfo *II, MacroInfo *MI);
@@ -537,7 +537,7 @@ public:
   /// history table. Currently defined macros have
   /// IdentifierInfo::hasMacroDefinition() set and an empty
   /// MacroInfo::getUndefLoc() at the head of the list.
-  typedef llvm::DenseMap<IdentifierInfo*,
+  typedef llvm::DenseMap<const IdentifierInfo *,
                          MacroInfo*>::const_iterator macro_iterator;
   macro_iterator macro_begin(bool IncludeExternalMacros = true) const;
   macro_iterator macro_end(bool IncludeExternalMacros = true) const;
diff --git a/include/clang/Sema/CodeCompleteConsumer.h b/include/clang/Sema/CodeCompleteConsumer.h
index 2eb9170369..2a8da3260a 100644
--- a/include/clang/Sema/CodeCompleteConsumer.h
+++ b/include/clang/Sema/CodeCompleteConsumer.h
@@ -661,7 +661,7 @@ public:
     CodeCompletionString *Pattern;
 
     /// \brief When Kind == RK_Macro, the identifier that refers to a macro.
-    IdentifierInfo *Macro;
+    const IdentifierInfo *Macro;
   };
 
   /// \brief The priority of this particular code-completion result.
@@ -728,7 +728,8 @@ public:
   }
 
   /// \brief Build a result that refers to a macro.
-  CodeCompletionResult(IdentifierInfo *Macro, unsigned Priority = CCP_Macro)
+  CodeCompletionResult(const IdentifierInfo *Macro,
+                       unsigned Priority = CCP_Macro)
     : Declaration(0), Macro(Macro), Priority(Priority), StartParameter(0),
       Kind(RK_Macro), CursorKind(CXCursor_MacroDefinition),
       Availability(CXAvailability_Available), Hidden(false),
diff --git a/lib/Frontend/PrintPreprocessedOutput.cpp b/lib/Frontend/PrintPreprocessedOutput.cpp
index 02da71bbbe..cc8d935b52 100644
--- a/lib/Frontend/PrintPreprocessedOutput.cpp
+++ b/lib/Frontend/PrintPreprocessedOutput.cpp
@@ -565,7 +565,7 @@ static void PrintPreprocessedTokens(Preprocessor &PP, Token &Tok,
   }
 }
 
-typedef std::pair<IdentifierInfo*, MacroInfo*> id_macro_pair;
+typedef std::pair<const IdentifierInfo *, MacroInfo *> id_macro_pair;
 static int MacroIDCompare(const void* a, const void* b) {
   const id_macro_pair *LHS = static_cast<const id_macro_pair*>(a);
   const id_macro_pair *RHS = static_cast<const id_macro_pair*>(b);
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index eb08977ee6..c626b4d561 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -32,7 +32,7 @@
 #include <ctime>
 using namespace clang;
 
-MacroInfo *Preprocessor::getMacroInfoHistory(IdentifierInfo *II) const {
+MacroInfo *Preprocessor::getMacroInfoHistory(const IdentifierInfo *II) const {
   assert(II->hadMacroDefinition() && "Identifier has not been not a macro!");
 
   macro_iterator Pos = Macros.find(II);
diff --git a/tools/libclang/CIndex.cpp b/tools/libclang/CIndex.cpp
index 3237d22d78..33811d0fb7 100644
--- a/tools/libclang/CIndex.cpp
+++ b/tools/libclang/CIndex.cpp
@@ -6233,7 +6233,7 @@ MacroInfo *cxindex::getMacroInfo(const IdentifierInfo &II,
 
   ASTUnit *Unit = static_cast<ASTUnit *>(TU->TUData);
   Preprocessor &PP = Unit->getPreprocessor();
-  MacroInfo *MI = PP.getMacroInfoHistory(const_cast<IdentifierInfo*>(&II));
+  MacroInfo *MI = PP.getMacroInfoHistory(&II);
   while (MI) {
     if (MacroDefLoc == MI->getDefinitionLoc())
       return MI;
diff --git a/tools/libclang/CXCursor.cpp b/tools/libclang/CXCursor.cpp
index f4faab313b..7134dc4189 100644
--- a/tools/libclang/CXCursor.cpp
+++ b/tools/libclang/CXCursor.cpp
@@ -1056,7 +1056,7 @@ CXCompletionString clang_getCursorCompletionString(CXCursor cursor) {
     const MacroDefinition *definition = getCursorMacroDefinition(cursor);
     const IdentifierInfo *MacroInfo = definition->getName();
     ASTUnit *unit = getCursorASTUnit(cursor);
-    CodeCompletionResult Result(const_cast<IdentifierInfo *>(MacroInfo));
+    CodeCompletionResult Result(MacroInfo);
     CodeCompletionString *String
       = Result.CreateCodeCompletionString(unit->getASTContext(),
                                           unit->getPreprocessor(),