diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index ac86d41..d38b530 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -1,4 +1,4 @@
-//===--- ASTReader.cpp - AST File Reader ------------------------*- C++ -*-===//
+//===--- ASTReader.cpp - AST File Reader ----------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -5963,7 +5963,7 @@
 }
 
 void ASTReader::ReadUndefinedInternals(
-                       llvm::MapVector<NamedDecl*, SourceLocation> &Undefined) {
+                        llvm::DenseMap<NamedDecl*, SourceLocation> &Undefined) {
   for (unsigned Idx = 0, N = UndefinedInternals.size(); Idx != N;) {
     NamedDecl *D = cast<NamedDecl>(GetDecl(UndefinedInternals[Idx++]));
     SourceLocation Loc =
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 25e3d52..8120799 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -3590,10 +3590,11 @@
 
   // Build a record of all used, undefined objects with internal linkage.
   RecordData UndefinedInternals;
-  for (llvm::MapVector<NamedDecl*, SourceLocation>::iterator
-            I = SemaRef.UndefinedInternals.begin(),
-         IEnd = SemaRef.UndefinedInternals.end();
-       I != IEnd; ++I) {
+
+  SmallVector<std::pair<NamedDecl *, SourceLocation>, 16> Undefined;
+  SemaRef.getUndefinedInternals(Undefined);
+  for (SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> >::iterator
+         I = Undefined.begin(), E = Undefined.end(); I != E; ++I) {
     AddDeclRef(I->first, UndefinedInternals);
     AddSourceLocation(I->second, UndefinedInternals);
   }