diff --git a/lib/Frontend/PCHWriter.cpp b/lib/Frontend/PCHWriter.cpp
index 41a5025..3bfc9e8 100644
--- a/lib/Frontend/PCHWriter.cpp
+++ b/lib/Frontend/PCHWriter.cpp
@@ -374,7 +374,8 @@
   RECORD(STAT_CACHE);
   RECORD(EXT_VECTOR_DECLS);
   RECORD(OBJC_CATEGORY_IMPLEMENTATIONS);
-
+  RECORD(COMMENT_RANGES);
+  
   // SourceManager Block.
   BLOCK(SOURCE_MANAGER_BLOCK);
   RECORD(SM_SLOC_FILE_ENTRY);
@@ -989,6 +990,24 @@
   Stream.ExitBlock();
 }
 
+void PCHWriter::WriteComments(ASTContext &Context) {
+  using namespace llvm;
+  
+  if (Context.Comments.empty())
+    return;
+  
+  BitCodeAbbrev *CommentAbbrev = new BitCodeAbbrev();
+  CommentAbbrev->Add(BitCodeAbbrevOp(pch::COMMENT_RANGES));
+  CommentAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
+  unsigned CommentCode = Stream.EmitAbbrev(CommentAbbrev);
+  
+  RecordData Record;
+  Record.push_back(pch::COMMENT_RANGES);
+  Stream.EmitRecordWithBlob(CommentCode, Record, 
+                            (const char*)&Context.Comments[0],
+                            Context.Comments.size() * sizeof(SourceRange));
+}
+
 //===----------------------------------------------------------------------===//
 // Type Serialization
 //===----------------------------------------------------------------------===//
@@ -1746,7 +1765,8 @@
     WriteStatCache(*StatCalls);
   WriteSourceManagerBlock(Context.getSourceManager(), PP);
   WritePreprocessor(PP);
-
+  WriteComments(Context);  
+  
   // Keep writing types and declarations until all types and
   // declarations have been written.
   do {