diff --git a/libs/ardour/ardour/audio_diskstream.h b/libs/ardour/ardour/audio_diskstream.h
index 2614b8061c..f93c949a38 100644
--- a/libs/ardour/ardour/audio_diskstream.h
+++ b/libs/ardour/ardour/audio_diskstream.h
@@ -125,7 +125,6 @@ class LIBARDOUR_API AudioDiskstream : public Diskstream
 		}
 	}
 
-	CubicInterpolation interpolation;
 
   protected:
 	friend class Session;
@@ -205,6 +204,8 @@ class LIBARDOUR_API AudioDiskstream : public Diskstream
 
 	typedef std::vector<ChannelInfo*> ChannelList;
 
+	CubicInterpolation interpolation;
+
 	/* The two central butler operations */
 	int do_flush (RunContext context, bool force = false);
 	int do_refill () { return _do_refill(_mixdown_buffer, _gain_buffer); }