diff --git a/pkg/obioptions/version.go b/pkg/obioptions/version.go
index dd74f62..1f7b858 100644
--- a/pkg/obioptions/version.go
+++ b/pkg/obioptions/version.go
@@ -8,7 +8,7 @@ import (
 // corresponds to the last commit, and not the one when the file will be
 // commited
 
-var _Commit = "5150947"
+var _Commit = "7f4ebe7"
 var _Version = "Release 4.4.0"
 
 // Version returns the version of the obitools package.
diff --git a/pkg/obitools/obimatrix/obimatrix.go b/pkg/obitools/obimatrix/obimatrix.go
index 0a77159..2ff4aee 100644
--- a/pkg/obitools/obimatrix/obimatrix.go
+++ b/pkg/obitools/obimatrix/obimatrix.go
@@ -123,7 +123,7 @@ func (data *MatrixData) Update(s *obiseq.BioSequence, mapkey string, strict bool
 		ok := false
 		switch attrname {
 		case "id":
-			value = s.Id
+			value = s.Id()
 			ok = true
 		case "count":
 			value = s.Count()