diff --git a/src/factory.cc b/src/factory.cc
index cccc3e7629..da85b12fc8 100644
--- a/src/factory.cc
+++ b/src/factory.cc
@@ -310,8 +310,7 @@ Handle<String> ConcatStringContent(Handle<StringType> result,
 Handle<String> Factory::NewFlatConcatString(Handle<String> first,
                                             Handle<String> second) {
   int total_length = first->length() + second->length();
-  if (first->IsOneByteRepresentationUnderneath() &&
-      second->IsOneByteRepresentationUnderneath()) {
+  if (first->IsOneByteRepresentation() && second->IsOneByteRepresentation()) {
     return ConcatStringContent<uint8_t>(
         NewRawOneByteString(total_length), first, second);
   } else {
diff --git a/src/objects.cc b/src/objects.cc
index 441c25e70c..e5b4763240 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -8339,11 +8339,6 @@ SmartArrayPointer<char> String::ToCString(AllowNullsFlag allow_nulls,
 }
 
 
-const uc16* String::GetTwoByteData() {
-  return GetTwoByteData(0);
-}
-
-
 const uc16* String::GetTwoByteData(unsigned start) {
   ASSERT(!IsOneByteRepresentationUnderneath());
   switch (StringShape(this).representation_tag()) {
diff --git a/src/objects.h b/src/objects.h
index 3105579e28..0099cb2095 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -8611,7 +8611,6 @@ class String: public Name {
   static const int kMaxShortPrintLength = 1024;
 
   // Support for regular expressions.
-  const uc16* GetTwoByteData();
   const uc16* GetTwoByteData(unsigned start);
 
   // Helper function for flattening strings.