diff --git a/libs/ardour/audio_diskstream.cc b/libs/ardour/audio_diskstream.cc
index 0d2c664e48..e0086fa295 100644
--- a/libs/ardour/audio_diskstream.cc
+++ b/libs/ardour/audio_diskstream.cc
@@ -148,6 +148,8 @@ AudioDiskstream::free_working_buffers()
 void
 AudioDiskstream::non_realtime_input_change ()
 {
+	bool need_new_write_sources = false;
+
 	{
 		Glib::Threads::Mutex::Lock lm (state_lock);
 
@@ -166,6 +168,8 @@ AudioDiskstream::non_realtime_input_change ()
 			} else if (_io->n_ports().n_audio() < _n_channels.n_audio()) {
 				remove_channel_from (c, _n_channels.n_audio() - _io->n_ports().n_audio());
 			}
+
+			need_new_write_sources = true;
 		}
 
 		if (input_change_pending.type & IOChange::ConnectionsChanged) {
@@ -179,9 +183,9 @@ AudioDiskstream::non_realtime_input_change ()
 		/* implicit unlock */
 	}
 
-	/* reset capture files */
-
-	reset_write_sources (false);
+	if (need_new_write_sources) {
+		reset_write_sources (false);
+	}
 
 	/* now refill channel buffers */