diff --git a/gtk2_ardour/automation_controller.cc b/gtk2_ardour/automation_controller.cc
index e1e16a7848..f57f2a737a 100644
--- a/gtk2_ardour/automation_controller.cc
+++ b/gtk2_ardour/automation_controller.cc
@@ -84,6 +84,7 @@ AutomationController::AutomationController(boost::shared_ptr<Automatable>
 		} else {
 			but->set_name("generic button");
 		}
+		but->set_controllable(ac);
 		but->signal_clicked.connect(
 			sigc::mem_fun(*this, &AutomationController::toggled));