diff --git a/gtk2_ardour/ardour_ui.cc b/gtk2_ardour/ardour_ui.cc
index 931ceadd21..cdf8099fd0 100644
--- a/gtk2_ardour/ardour_ui.cc
+++ b/gtk2_ardour/ardour_ui.cc
@@ -660,6 +660,7 @@ ARDOUR_UI::startup ()
 	app->ready ();
 
 	nsm_url = getenv ("NSM_URL");
+	nsm = 0;
 
 	if (nsm_url) {
 		nsm = new NSM_Client;