diff --git a/libs/temporal/tempo.cc b/libs/temporal/tempo.cc
index 2fa2f67a8b..54f2823120 100644
--- a/libs/temporal/tempo.cc
+++ b/libs/temporal/tempo.cc
@@ -2966,3 +2966,20 @@ TempoMap::init ()
 	_map_mgr.init (new_map);
 	fetch ();
 }
+
+void
+TempoMap::update (TempoMap::SharedPtr m)
+{
+	cerr << "SWITCHING TEMPO MAP FROM:\n";
+	TempoMap::SharedPtr old (_map_mgr.reader());
+	old->dump (cerr);
+	cerr << " TO\n";
+	m->dump (cerr);
+
+	_map_mgr.update (m);
+
+	/* update thread local map pointer in the calling thread */
+	_tempo_map_p = _map_mgr.reader();
+
+	MapChanged (); /* EMIT SIGNAL */
+}
diff --git a/libs/temporal/temporal/tempo.h b/libs/temporal/temporal/tempo.h
index 0cb4ffc2ab..12da8ad9f1 100644
--- a/libs/temporal/temporal/tempo.h
+++ b/libs/temporal/temporal/tempo.h
@@ -645,7 +645,7 @@ class LIBTEMPORAL_API TempoMap : public PBD::StatefulDestructible
 
 	static SharedPtr write_copy() { return _map_mgr.write_copy(); }
 	static void fetch_writable() { _tempo_map_p = write_copy(); }
-	static void update (SharedPtr m) { _map_mgr.update (m); _tempo_map_p = _map_mgr.reader(); }
+	static void update (SharedPtr m);
 
 	/* and now on with the rest of the show ... */