diff --git a/libs/ardour/disk_writer.cc b/libs/ardour/disk_writer.cc
index 1dd0a2dd79..c0d9408954 100644
--- a/libs/ardour/disk_writer.cc
+++ b/libs/ardour/disk_writer.cc
@@ -55,6 +55,8 @@ DiskWriter::DiskWriter (Session& s, string const & str, DiskIOProcessor::Flag f)
 	, last_recordable_sample (max_samplepos)
 	, last_possibly_recording (0)
 	, _alignment_style (ExistingMaterial)
+	, _note_mode (Sustained)
+	, _samples_pending_write (0)
 	, _num_captured_loops (0)
 	, _accumulated_capture_offset (0)
 	, _gui_feed_buffer(AudioEngine::instance()->raw_buffer_size (DataType::MIDI))