diff --git a/cpp11-migrate/AddOverride/AddOverrideActions.cpp b/cpp11-migrate/AddOverride/AddOverrideActions.cpp
index a40f673..3d1f1ff 100644
--- a/cpp11-migrate/AddOverride/AddOverrideActions.cpp
+++ b/cpp11-migrate/AddOverride/AddOverrideActions.cpp
@@ -1,59 +1,63 @@
 //===-- AddOverride/AddOverrideActions.cpp - add C++11 override-*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 ///  \file
 ///  \brief This file contains the definition of the AddOverrideFixer class
 ///  which is used as an ASTMatcher callback.
 ///
 //===----------------------------------------------------------------------===//
 
 #include "AddOverrideActions.h"
 #include "AddOverrideMatchers.h"
 
 #include "clang/Basic/CharInfo.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/Attr.h"
 #include "clang/AST/RecursiveASTVisitor.h"
 #include "clang/Lex/Lexer.h"
 
 using namespace clang::ast_matchers;
 using namespace clang::tooling;
 using namespace clang;
 
 void AddOverrideFixer::run(const MatchFinder::MatchResult &Result) {
   SourceManager &SM = *Result.SourceManager;
 
   const CXXMethodDecl *M = Result.Nodes.getDeclAs<CXXMethodDecl>(MethodId);
   assert(M && "Bad Callback. No node provided");
 
+  // Check that the method declaration in the main file
+  if (!SM.isFromMainFile(M->getLocStart()))
+    return;
+
   // First check that there isn't already an override attribute.
   if (!M->hasAttr<OverrideAttr>()) {
     if (M->getLocStart().isFileID()) {
       SourceLocation StartLoc;
       if (M->hasInlineBody()) {
         // Start at the beginning of the body and rewind back to the last
         // non-whitespace character. We will insert the override keyword
         // after that character.
         // FIXME: This transform won't work if there is a comment between
         // the end of the function prototype and the start of the body.
         StartLoc = M->getBody()->getLocStart();
         do {
           StartLoc = StartLoc.getLocWithOffset(-1);
         } while (isWhitespace(*FullSourceLoc(StartLoc, SM).getCharacterData()));
         StartLoc = StartLoc.getLocWithOffset(1);
       } else {
         StartLoc = SM.getSpellingLoc(M->getLocEnd());
         StartLoc = Lexer::getLocForEndOfToken(StartLoc, 0, SM, LangOptions());
       }
       Replace.insert(tooling::Replacement(SM, StartLoc, 0, " override"));
       ++AcceptedChanges;
     }
   }
 }