diff --git a/lib/Frontend/FrontendActions.cpp b/lib/Frontend/FrontendActions.cpp
index 47063f7..c28593f 100644
--- a/lib/Frontend/FrontendActions.cpp
+++ b/lib/Frontend/FrontendActions.cpp
@@ -273,19 +273,11 @@
     CI.getPreprocessor().getHeaderSearchInfo().getModuleMap(),
     Module, HeaderContents);
 
-  StringRef InputName = Module::getModuleInputBufferName();
-
-  // We consistently construct a buffer as input to build the module.
-  // This means the main file for modules will always be a virtual one.
-  // FIXME: Maybe allow using a memory buffer as input directly instead of
-  // messing with virtual files.
-  const FileEntry *HeaderFile = FileMgr.getVirtualFile(InputName, 
-                                                       HeaderContents.size(), 
-                                                       time(0));
-  llvm::MemoryBuffer *HeaderContentsBuf
-    = llvm::MemoryBuffer::getMemBufferCopy(HeaderContents);
-  CI.getSourceManager().overrideFileContents(HeaderFile, HeaderContentsBuf);  
-  setCurrentInput(FrontendInputFile(InputName, getCurrentFileKind(),
+  llvm::MemoryBuffer *InputBuffer =
+      llvm::MemoryBuffer::getMemBufferCopy(HeaderContents,
+                                           Module::getModuleInputBufferName());
+  // Ownership of InputBuffer will be transfered to the SourceManager.
+  setCurrentInput(FrontendInputFile(InputBuffer, getCurrentFileKind(),
                                     Module->IsSystem));
   return true;
 }
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index cd15e21..6e82cd9 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -1796,6 +1796,10 @@
       MaybeAddSystemRootToFilename(F, F.OriginalSourceFileName);
       break;
 
+    case ORIGINAL_FILE_ID:
+      F.OriginalSourceFileID = FileID::get(Record[0]);
+      break;
+
     case ORIGINAL_PCH_DIR:
       F.OriginalDir.assign(BlobStart, BlobLen);
       break;
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index f06b428..744ae9f 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -777,6 +777,7 @@
   RECORD(TARGET_OPTIONS);
   RECORD(ORIGINAL_FILE);
   RECORD(ORIGINAL_PCH_DIR);
+  RECORD(ORIGINAL_FILE_ID);
   RECORD(INPUT_FILE_OFFSETS);
   RECORD(DIAGNOSTIC_OPTIONS);
   RECORD(FILE_SYSTEM_OPTIONS);
@@ -1180,6 +1181,10 @@
     Stream.EmitRecordWithBlob(FileAbbrevCode, Record, MainFileNameStr);
   }
 
+  Record.clear();
+  Record.push_back(SM.getMainFileID().getOpaqueValue());
+  Stream.EmitRecord(ORIGINAL_FILE_ID, Record);
+
   // Original PCH directory
   if (!OutputFile.empty() && OutputFile != "-") {
     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();