diff --git a/pkg/obingslibrary/marker.go b/pkg/obingslibrary/marker.go
index 0518828..307a288 100644
--- a/pkg/obingslibrary/marker.go
+++ b/pkg/obingslibrary/marker.go
@@ -312,7 +312,7 @@ func normalizeTagDelimiter(delim byte) byte {
 		delim = 0
 	} else {
 		if delim >= 'A' && delim <= 'Z' {
-			delim = delim + 'A' - 'a'
+			delim = delim - 'A' + 'a'
 		}
 		if delim != 'a' && delim != 'c' && delim != 'g' && delim != 't' {
 			log.Fatalf("invalid reverse tag delimiter: %c, only 'a', 'c', 'g', 't' and '0' are allowed", delim)
diff --git a/pkg/obioptions/version.go b/pkg/obioptions/version.go
index 869f631..f4af4eb 100644
--- a/pkg/obioptions/version.go
+++ b/pkg/obioptions/version.go
@@ -7,7 +7,7 @@ import (
 // TODO: The version number is extracted from git. This induces that the version
 // corresponds to the last commit, and not the one when the file will be
 // commited
-var _Commit = "d600713"
+var _Commit = "170593b"
 var _Version = "Release 4.2.0"
 
 // Version returns the version of the obitools package.