diff --git a/gtk2_ardour/plugin_eq_gui.cc b/gtk2_ardour/plugin_eq_gui.cc
index 3115f54c41..1fa5d2d598 100644
--- a/gtk2_ardour/plugin_eq_gui.cc
+++ b/gtk2_ardour/plugin_eq_gui.cc
@@ -79,10 +79,7 @@ PluginEqGui::PluginEqGui(boost::shared_ptr<ARDOUR::PluginInsert> pluginInsert)
 	// dB selection
 	dBScaleModel = Gtk::ListStore::create(dBColumns);
 
-	/* this grotty-looking cast allows compilation against gtkmm 2.24.0, which
-	   added a new ComboBox constructor.
-	*/
-	dBScaleCombo = new Gtk::ComboBox ((Glib::RefPtr<Gtk::TreeModel> &) dBScaleModel);
+	dBScaleCombo = new Gtk::ComboBox (dBScaleModel, false);
 	dBScaleCombo->set_title (_("dB scale"));
 
 #define ADD_DB_ROW(MIN,MAX,STEP,NAME) \