diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index d04f785..4cd9280 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -81,6 +81,10 @@
   return dyn_cast<PCHReader>(Ctx->getExternalSource())->getOriginalSourceFile();
 }
 
+FileManager &ASTUnit::getFileManager() {
+  return HeaderInfo->getFileMgr();
+}
+
 ASTUnit *ASTUnit::LoadFromPCHFile(const std::string &Filename,
                                   FileManager &FileMgr,
                                   std::string *ErrMsg) {