diff --git a/libs/ardour/ardour/delayline.h b/libs/ardour/ardour/delayline.h
index 56a6de0c63..9dfe5628d3 100644
--- a/libs/ardour/ardour/delayline.h
+++ b/libs/ardour/ardour/delayline.h
@@ -58,8 +58,8 @@ private:
 	framecnt_t _delay, _pending_delay;
 	framecnt_t _bsiz,  _pending_bsiz;
 	frameoffset_t _roff, _woff;
-	boost::shared_ptr<Sample> _buf;
-	boost::shared_ptr<Sample> _pending_buf;
+	boost::shared_ptr<Sample[]> _buf;
+	boost::shared_ptr<Sample[]> _pending_buf;
 	boost::shared_ptr<MidiBuffer> _midi_buf;
 	bool _pending_flush;
 };