diff --git a/pkg/obioptions/version.go b/pkg/obioptions/version.go
index 0de542a..7f851b0 100644
--- a/pkg/obioptions/version.go
+++ b/pkg/obioptions/version.go
@@ -3,7 +3,7 @@ package obioptions
 // Version is automatically updated by the Makefile from version.txt
 // The patch number (third digit) is incremented on each push to the repository
 
-var _Version = "Release 4.4.20"
+var _Version = "Release 4.4.21"
 
 // Version returns the version of the obitools package.
 //
diff --git a/version.txt b/version.txt
index d83088a..711adc7 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-4.4.20
+4.4.21