diff --git a/libs/ardour/sndfilesource.cc b/libs/ardour/sndfilesource.cc
index 1f499bc61e..4353c50eed 100644
--- a/libs/ardour/sndfilesource.cc
+++ b/libs/ardour/sndfilesource.cc
@@ -339,7 +339,7 @@ SndFileSource::read_unlocked (Sample *dst, framepos_t start, framecnt_t cnt) con
 			if (ret != file_cnt) {
 				char errbuf[256];
 				sf_error_str (0, errbuf, sizeof (errbuf) - 1);
-				error << string_compose(_("SndFileSource: @ %1 could not read %2 within %3 (%4) (len = %5)"), start, file_cnt, _name.val().substr (1), errbuf, _length) << endl;
+				error << string_compose(_("SndFileSource: @ %1 could not read %2 within %3 (%4) (len = %5, ret was %6)"), start, file_cnt, _name.val().substr (1), errbuf, _length, ret) << endl;
 			}
 			_descriptor->release ();
 			return ret;