diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 41381e7494..bca3970f08 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -1375,6 +1375,7 @@ public:
 	void trigger_cue_row (int32_t);
 	CueEvents const & cue_events() const { return _cue_events; }
 
+	int num_triggerboxes () const;
 	boost::shared_ptr<TriggerBox> triggerbox_at (int32_t route_index) const;
 	TriggerPtr trigger_at (int32_t route_index, int32_t row_index) const;
 	bool bang_trigger_at(int32_t route_index, int32_t row_index);
diff --git a/libs/ardour/session_process.cc b/libs/ardour/session_process.cc
index 1ab2776b73..3fce1713ea 100644
--- a/libs/ardour/session_process.cc
+++ b/libs/ardour/session_process.cc
@@ -1806,6 +1806,26 @@ Session::triggerbox_at (int32_t route_index) const
 	return boost::shared_ptr<TriggerBox>();
 }
 
+int
+Session::num_triggerboxes () const
+{
+	int count = 0;
+	StripableList sl;
+	get_stripables (sl);
+	for (StripableList::iterator s = sl.begin (); s != sl.end (); ++s) {
+		boost::shared_ptr<Route>     r = boost::dynamic_pointer_cast<Route> (*s);
+		if (!r || !r->triggerbox ()) {
+			continue;
+		}
+		/* we're only interested in Trigger Tracks */
+		if (!(r->presentation_info ().trigger_track ())) {
+			continue;
+		}
+		count++;
+	}
+	return count;
+}
+
 TriggerPtr
 Session::trigger_at (int32_t route_index, int32_t trigger_index) const
 {