diff --git a/common/server_database_interface.h b/common/server_database_interface.h
index b97d1021..0cabe867 100644
--- a/common/server_database_interface.h
+++ b/common/server_database_interface.h
@@ -25,7 +25,7 @@ public:
     virtual DeckList *getDeckFromDatabase(int /* deckId */, int /* userId */) { return 0; }
     
     virtual qint64 startSession(const QString & /* userName */, const QString & /* address */) { return 0; }
-    virtual bool usernameIsValid(const QString &userName) { return true; };
+    virtual bool usernameIsValid(const QString & /*userName */) { return true; };
 public slots:
     virtual void endSession(qint64 /* sessionId */ ) { }
 public: