diff --git a/rbutil/rbutilqt/install.cpp b/rbutil/rbutilqt/install.cpp
index 69a03f8091..457ea0d59f 100644
--- a/rbutil/rbutilqt/install.cpp
+++ b/rbutil/rbutilqt/install.cpp
@@ -268,7 +268,7 @@ void Install::setDetailsArchived(bool show)
 
 
 
-void Install::setVersionStrings(QMap<QString, QString> ver)
+void Install::setVersionStrings(QMap<QString, QString>& ver)
 {
     version = ver;
     // version strings map is as following:
diff --git a/rbutil/rbutilqt/install.h b/rbutil/rbutilqt/install.h
index 2f116f269a..720b8ea14a 100644
--- a/rbutil/rbutilqt/install.h
+++ b/rbutil/rbutilqt/install.h
@@ -34,7 +34,7 @@ class Install : public QDialog
     Q_OBJECT
     public:
         Install(RbSettings* sett,QWidget *parent = 0);
-        void setVersionStrings(QMap<QString, QString>);
+        void setVersionStrings(QMap<QString, QString>&);
 
     public slots:
         void accept(void);