diff --git a/libs/ardour/disk_reader.cc b/libs/ardour/disk_reader.cc
index d90ec3b546..8af7d079ec 100644
--- a/libs/ardour/disk_reader.cc
+++ b/libs/ardour/disk_reader.cc
@@ -1019,6 +1019,7 @@ DiskReader::audio_read (Sample*            sum_buffer,
 
 	if (reversed) {
 		start -= cnt;
+		start = max (samplepos_t (0), start);
 	}
 
 	/* We need this while loop in case we hit a loop boundary, in which case our read from