diff --git a/src/database.cc b/src/database.cc
index f2c9e242..121977b8 100644
--- a/src/database.cc
+++ b/src/database.cc
@@ -20,7 +20,7 @@ namespace leveldown {
 
 static v8::Persistent<v8::FunctionTemplate> database_constructor;
 
-Database::Database (v8::Handle<v8::Value> from)
+Database::Database (const v8::Handle<v8::Value>& from)
   : location(new NanUtf8String(from))
   , db(NULL)
   , currentIteratorId(0)
diff --git a/src/database.h b/src/database.h
index c6579cb1..7940d44c 100644
--- a/src/database.h
+++ b/src/database.h
@@ -75,7 +75,7 @@ class Database : public node::ObjectWrap {
   void CloseDatabase ();
   void ReleaseIterator (uint32_t id);
 
-  Database (v8::Handle<v8::Value> from);
+  Database (const v8::Handle<v8::Value>& from);
   ~Database ();
 
 private: