diff --git a/libs/ardour/mtc_slave.cc b/libs/ardour/mtc_slave.cc
index d3dcb386c5..7d6416b5d6 100644
--- a/libs/ardour/mtc_slave.cc
+++ b/libs/ardour/mtc_slave.cc
@@ -482,6 +482,8 @@ MTC_Slave::resolution() const
 void
 MTC_Slave::queue_reset ()
 {
+	DEBUG_TRACE (DEBUG::MTC, "queue reset of MTC slave state\n");
+	PBD::stacktrace (cerr, 35);
 	Glib::Mutex::Lock lm (reset_lock);
 	reset_pending++;
 }