diff --git a/pkg/obiformats/fastseq_obi_header.go b/pkg/obiformats/fastseq_obi_header.go
index 05d76bd..f8e2e3c 100644
--- a/pkg/obiformats/fastseq_obi_header.go
+++ b/pkg/obiformats/fastseq_obi_header.go
@@ -18,6 +18,7 @@ import (
 
 var __obi_header_value_string_pattern__ = regexp.MustCompile(`^'\s*([^']*'|"[^"]*")\s*;`)
 var __obi_header_value_numeric_pattern__ = regexp.MustCompile(`^\s*([+-]?\.\d+|[+-]?\d+(\.\d*)?([eE][+-]?\d+)?)\s*;`)
+var __obi_header_map_int_key__ = regexp.MustCompile("([{,])([0-9]+):")
 
 func __match__dict__(text []byte) []int {
 
@@ -212,6 +213,7 @@ func ParseOBIFeatures(text string, annotations obiseq.Annotation) string {
 				if len(m) > 0 {
 					bvalue = bytes.TrimSpace(part[m[0]:(m[1] - 1)])
 					j := bytes.ReplaceAll(bvalue, []byte("'"), []byte(`"`))
+					j = __obi_header_map_int_key__.ReplaceAll(j, []byte(`$1"$2":`))
 					var err error
 					switch {
 					case strings.HasPrefix(key, "merged_") ||
diff --git a/pkg/obioptions/version.go b/pkg/obioptions/version.go
index d3ad99c..9ae19f5 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 = "5a3705b"
+var _Commit = "fd80249"
 var _Version = "Release 4.4.0"
 
 // Version returns the version of the obitools package.