diff --git a/src/Storage.h b/src/Storage.h
index 3a28b36d0e..6f913a55b1 100644
--- a/src/Storage.h
+++ b/src/Storage.h
@@ -22,6 +22,8 @@
 
 namespace nt {
 
+class StorageTest;
+
 class StorageEntry {
  public:
   StorageEntry() : m_flags(0), m_id(0xffff) {}
@@ -70,6 +72,7 @@ class StorageEntry {
 };
 
 class Storage {
+  friend class StorageTest;
  public:
   static Storage& GetInstance() {
     if (!m_instance) m_instance.reset(new Storage);
@@ -77,8 +80,6 @@ class Storage {
   }
   ~Storage();
 
-  typedef llvm::StringMap<std::shared_ptr<StorageEntry>> EntriesMap;
-
   struct Update {
     std::shared_ptr<StorageEntry> entry;
     enum Kind { kAssign, kValueUpdate, kFlagsUpdate, kDelete, kDeleteAll };
@@ -111,6 +112,8 @@ class Storage {
   Storage(const Storage&) = delete;
   Storage& operator=(const Storage&) = delete;
 
+  typedef llvm::StringMap<std::shared_ptr<StorageEntry>> EntriesMap;
+
   mutable std::mutex m_mutex;
   EntriesMap m_entries;
   UpdateQueue m_updates;