diff --git a/src/google/protobuf/extension_set.cc b/src/google/protobuf/extension_set.cc
index 649ae184..919bd83b 100644
--- a/src/google/protobuf/extension_set.cc
+++ b/src/google/protobuf/extension_set.cc
@@ -34,7 +34,6 @@
 
 #include <google/protobuf/stubs/hash.h>
 #include <google/protobuf/stubs/common.h>
-#include <google/protobuf/stubs/once.h>
 #include <google/protobuf/extension_set.h>
 #include <google/protobuf/message_lite.h>
 #include <google/protobuf/io/coded_stream.h>
@@ -1747,66 +1746,68 @@ void ExtensionSet::Extension::Free() {
 // ==================================================================
 // Default repeated field instances for iterator-compatible accessors
 
+GOOGLE_PROTOBUF_DECLARE_ONCE(repeated_primitive_generic_type_traits_once_init_);
+GOOGLE_PROTOBUF_DECLARE_ONCE(repeated_string_type_traits_once_init_);
+GOOGLE_PROTOBUF_DECLARE_ONCE(repeated_message_generic_type_traits_once_init_);
+
+void RepeatedPrimitiveGenericTypeTraits::InitializeDefaultRepeatedFields() {
+  default_repeated_field_int32_ = new RepeatedField<int32>;
+  default_repeated_field_int64_ = new RepeatedField<int64>;
+  default_repeated_field_uint32_ = new RepeatedField<uint32>;
+  default_repeated_field_uint64_ = new RepeatedField<uint64>;
+  default_repeated_field_double_ = new RepeatedField<double>;
+  default_repeated_field_float_ = new RepeatedField<float>;
+  default_repeated_field_bool_ = new RepeatedField<bool>;
+  OnShutdown(&DestroyDefaultRepeatedFields);
+}
+
+void RepeatedPrimitiveGenericTypeTraits::DestroyDefaultRepeatedFields() {
+  delete default_repeated_field_int32_;
+  delete default_repeated_field_int64_;
+  delete default_repeated_field_uint32_;
+  delete default_repeated_field_uint64_;
+  delete default_repeated_field_double_;
+  delete default_repeated_field_float_;
+  delete default_repeated_field_bool_;
+}
+
+void RepeatedStringTypeTraits::InitializeDefaultRepeatedFields() {
+  default_repeated_field_ = new RepeatedFieldType;
+  OnShutdown(&DestroyDefaultRepeatedFields);
+}
+
+void RepeatedStringTypeTraits::DestroyDefaultRepeatedFields() {
+  delete default_repeated_field_;
+}
+
+void RepeatedMessageGenericTypeTraits::InitializeDefaultRepeatedFields() {
+  default_repeated_field_ = new RepeatedFieldType;
+  OnShutdown(&DestroyDefaultRepeatedFields);
+}
+
+void RepeatedMessageGenericTypeTraits::DestroyDefaultRepeatedFields() {
+  delete default_repeated_field_;
+}
+
+const RepeatedField<int32>*
+RepeatedPrimitiveGenericTypeTraits::default_repeated_field_int32_ = NULL;
+const RepeatedField<int64>*
+RepeatedPrimitiveGenericTypeTraits::default_repeated_field_int64_ = NULL;
+const RepeatedField<uint32>*
+RepeatedPrimitiveGenericTypeTraits::default_repeated_field_uint32_ = NULL;
+const RepeatedField<uint64>*
+RepeatedPrimitiveGenericTypeTraits::default_repeated_field_uint64_ = NULL;
+const RepeatedField<double>*
+RepeatedPrimitiveGenericTypeTraits::default_repeated_field_double_ = NULL;
+const RepeatedField<float>*
+RepeatedPrimitiveGenericTypeTraits::default_repeated_field_float_ = NULL;
+const RepeatedField<bool>*
+RepeatedPrimitiveGenericTypeTraits::default_repeated_field_bool_ = NULL;
 const RepeatedStringTypeTraits::RepeatedFieldType*
 RepeatedStringTypeTraits::default_repeated_field_ = NULL;
-
 const RepeatedMessageGenericTypeTraits::RepeatedFieldType*
 RepeatedMessageGenericTypeTraits::default_repeated_field_ = NULL;
 
-#define PROTOBUF_DEFINE_DEFAULT_REPEATED(TYPE)                                 \
-    const RepeatedField<TYPE>*                                                 \
-    RepeatedPrimitiveGenericTypeTraits::default_repeated_field_##TYPE##_ = NULL;
-
-PROTOBUF_DEFINE_DEFAULT_REPEATED(int32)
-PROTOBUF_DEFINE_DEFAULT_REPEATED(int64)
-PROTOBUF_DEFINE_DEFAULT_REPEATED(uint32)
-PROTOBUF_DEFINE_DEFAULT_REPEATED(uint64)
-PROTOBUF_DEFINE_DEFAULT_REPEATED(double)
-PROTOBUF_DEFINE_DEFAULT_REPEATED(float)
-PROTOBUF_DEFINE_DEFAULT_REPEATED(bool)
-
-#undef PROTOBUF_DEFINE_DEFAULT_REPEATED
-
-struct StaticDefaultRepeatedFieldsInitializer {
-  StaticDefaultRepeatedFieldsInitializer() {
-    InitializeDefaultRepeatedFields();
-    OnShutdown(&DestroyDefaultRepeatedFields);
-  }
-} static_repeated_fields_initializer;
-
-void InitializeDefaultRepeatedFields() {
-  RepeatedStringTypeTraits::default_repeated_field_ =
-      new RepeatedStringTypeTraits::RepeatedFieldType;
-  RepeatedMessageGenericTypeTraits::default_repeated_field_ =
-      new RepeatedMessageGenericTypeTraits::RepeatedFieldType;
-  RepeatedPrimitiveGenericTypeTraits::default_repeated_field_int32_ =
-      new RepeatedField<int32>;
-  RepeatedPrimitiveGenericTypeTraits::default_repeated_field_int64_ =
-      new RepeatedField<int64>;
-  RepeatedPrimitiveGenericTypeTraits::default_repeated_field_uint32_ =
-      new RepeatedField<uint32>;
-  RepeatedPrimitiveGenericTypeTraits::default_repeated_field_uint64_ =
-      new RepeatedField<uint64>;
-  RepeatedPrimitiveGenericTypeTraits::default_repeated_field_double_ =
-      new RepeatedField<double>;
-  RepeatedPrimitiveGenericTypeTraits::default_repeated_field_float_ =
-      new RepeatedField<float>;
-  RepeatedPrimitiveGenericTypeTraits::default_repeated_field_bool_ =
-      new RepeatedField<bool>;
-}
-
-void DestroyDefaultRepeatedFields() {
-  delete RepeatedStringTypeTraits::default_repeated_field_;
-  delete RepeatedMessageGenericTypeTraits::default_repeated_field_;
-  delete RepeatedPrimitiveGenericTypeTraits::default_repeated_field_int32_;
-  delete RepeatedPrimitiveGenericTypeTraits::default_repeated_field_int64_;
-  delete RepeatedPrimitiveGenericTypeTraits::default_repeated_field_uint32_;
-  delete RepeatedPrimitiveGenericTypeTraits::default_repeated_field_uint64_;
-  delete RepeatedPrimitiveGenericTypeTraits::default_repeated_field_double_;
-  delete RepeatedPrimitiveGenericTypeTraits::default_repeated_field_float_;
-  delete RepeatedPrimitiveGenericTypeTraits::default_repeated_field_bool_;
-}
-
 }  // namespace internal
 }  // namespace protobuf
 }  // namespace google
diff --git a/src/google/protobuf/extension_set.h b/src/google/protobuf/extension_set.h
index c371e011..35f14b9c 100644
--- a/src/google/protobuf/extension_set.h
+++ b/src/google/protobuf/extension_set.h
@@ -45,6 +45,7 @@
 
 
 #include <google/protobuf/stubs/common.h>
+#include <google/protobuf/stubs/once.h>
 
 #include <google/protobuf/repeated_field.h>
 
@@ -716,15 +717,14 @@ class RepeatedPrimitiveTypeTraits {
   static const RepeatedFieldType* GetDefaultRepeatedField();
 };
 
-// Declared here so that this can be friended below.
-void InitializeDefaultRepeatedFields();
-void DestroyDefaultRepeatedFields();
+LIBPROTOBUF_EXPORT extern ProtobufOnceType
+repeated_primitive_generic_type_traits_once_init_;
 
 class LIBPROTOBUF_EXPORT RepeatedPrimitiveGenericTypeTraits {
  private:
   template<typename Type> friend class RepeatedPrimitiveTypeTraits;
-  friend void InitializeDefaultRepeatedFields();
-  friend void DestroyDefaultRepeatedFields();
+  static void InitializeDefaultRepeatedFields();
+  static void DestroyDefaultRepeatedFields();
   static const RepeatedField<int32>* default_repeated_field_int32_;
   static const RepeatedField<int64>* default_repeated_field_int64_;
   static const RepeatedField<uint32>* default_repeated_field_uint32_;
@@ -759,6 +759,9 @@ template<> inline void RepeatedPrimitiveTypeTraits<TYPE>::Add(             \
 }                                                                          \
 template<> inline const RepeatedField<TYPE>*                               \
     RepeatedPrimitiveTypeTraits<TYPE>::GetDefaultRepeatedField() {         \
+  GoogleOnceInit(                                                          \
+      &repeated_primitive_generic_type_traits_once_init_,                  \
+      &RepeatedPrimitiveGenericTypeTraits::InitializeDefaultRepeatedFields); \
   return RepeatedPrimitiveGenericTypeTraits::                              \
       default_repeated_field_##TYPE##_;                                    \
 }                                                                          \
@@ -812,6 +815,9 @@ class LIBPROTOBUF_EXPORT StringTypeTraits {
   }
 };
 
+LIBPROTOBUF_EXPORT extern ProtobufOnceType
+repeated_string_type_traits_once_init_;
+
 class LIBPROTOBUF_EXPORT RepeatedStringTypeTraits {
  public:
   typedef const string& ConstType;
@@ -855,12 +861,14 @@ class LIBPROTOBUF_EXPORT RepeatedStringTypeTraits {
   }
 
   static const RepeatedFieldType* GetDefaultRepeatedField() {
+    GoogleOnceInit(&repeated_string_type_traits_once_init_,
+                   &InitializeDefaultRepeatedFields);
     return default_repeated_field_;
   }
 
  private:
-  friend void InitializeDefaultRepeatedFields();
-  friend void DestroyDefaultRepeatedFields();
+  static void InitializeDefaultRepeatedFields();
+  static void DestroyDefaultRepeatedFields();
   static const RepeatedFieldType *default_repeated_field_;
 };
 
@@ -1019,6 +1027,9 @@ class RepeatedMessageTypeTraits {
   static const RepeatedFieldType* GetDefaultRepeatedField();
 };
 
+LIBPROTOBUF_EXPORT extern ProtobufOnceType
+repeated_message_generic_type_traits_once_init_;
+
 // This class exists only to hold a generic default empty repeated field for all
 // message-type repeated field extensions.
 class LIBPROTOBUF_EXPORT RepeatedMessageGenericTypeTraits {
@@ -1026,14 +1037,17 @@ class LIBPROTOBUF_EXPORT RepeatedMessageGenericTypeTraits {
   typedef RepeatedPtrField< ::google::protobuf::MessageLite*> RepeatedFieldType;
  private:
   template<typename Type> friend class RepeatedMessageTypeTraits;
-  friend void InitializeDefaultRepeatedFields();
-  friend void DestroyDefaultRepeatedFields();
+  static void InitializeDefaultRepeatedFields();
+  static void DestroyDefaultRepeatedFields();
   static const RepeatedFieldType* default_repeated_field_;
 };
 
 template<typename Type> inline
     const typename RepeatedMessageTypeTraits<Type>::RepeatedFieldType*
     RepeatedMessageTypeTraits<Type>::GetDefaultRepeatedField() {
+  GoogleOnceInit(
+      &repeated_message_generic_type_traits_once_init_,
+      &RepeatedMessageGenericTypeTraits::InitializeDefaultRepeatedFields);
   return reinterpret_cast<const RepeatedFieldType*>(
       RepeatedMessageGenericTypeTraits::default_repeated_field_);
 }