diff --git a/src/cpp/ripple/ripple_HashedObject.h b/src/cpp/ripple/ripple_HashedObject.h
index 963dcb2d9..2f3221719 100644
--- a/src/cpp/ripple/ripple_HashedObject.h
+++ b/src/cpp/ripple/ripple_HashedObject.h
@@ -38,6 +38,7 @@ class HashedObject : private IS_INSTANCE (HashedObject)
 {
 public:
     typedef boost::shared_ptr <HashedObject> pointer;
+    typedef pointer const& ref;
 
     /** Create from a vector of data.