diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 6bdca057badc..5e5999d5bf9c 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -4449,12 +4449,8 @@ bool ASTReader::ParseLanguageOptions(const RecordData &Record,
   ObjCRuntime::Kind runtimeKind = (ObjCRuntime::Kind) Record[Idx++];
   VersionTuple runtimeVersion = ReadVersionTuple(Record, Idx);
   LangOpts.ObjCRuntime = ObjCRuntime(runtimeKind, runtimeVersion);
-  
-  unsigned Length = Record[Idx++];
-  LangOpts.CurrentModule.assign(Record.begin() + Idx, 
-                                Record.begin() + Idx + Length);
 
-  Idx += Length;
+  LangOpts.CurrentModule = ReadString(Record, Idx);
 
   // Comment options.
   for (unsigned N = Record[Idx++]; N; --N) {
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index d6267767cf46..1a8d616efa8b 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -1272,9 +1272,8 @@ void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
 
   Record.push_back((unsigned) LangOpts.ObjCRuntime.getKind());
   AddVersionTuple(LangOpts.ObjCRuntime.getVersion(), Record);
-  
-  Record.push_back(LangOpts.CurrentModule.size());
-  Record.append(LangOpts.CurrentModule.begin(), LangOpts.CurrentModule.end());
+
+  AddString(LangOpts.CurrentModule, Record);
 
   // Comment options.
   Record.push_back(LangOpts.CommentOpts.BlockCommandNames.size());