diff --git a/libs/ardour/disk_writer.cc b/libs/ardour/disk_writer.cc
index 34aa3f1e9f..ad15081dcf 100644
--- a/libs/ardour/disk_writer.cc
+++ b/libs/ardour/disk_writer.cc
@@ -484,6 +484,8 @@ DiskWriter::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_samp
 		 */
 		if (rec_nframes) {
 			_accumulated_capture_offset += rec_offset;
+		} else {
+			_accumulated_capture_offset += nframes;
 		}
 
 	}