diff --git a/naheulbeuk.sb b/naheulbeuk.sb
index b42f2672..b5ad9399 100644
--- a/naheulbeuk.sb
+++ b/naheulbeuk.sb
@@ -1,5 +1,6 @@
 {
 "template" : "ancient.tmpl",
+"lang" : "french",
 "author" : "Crep (R.Goffe) \\and Lohrun (A.Dupas)",
 "bookoptions" : [
     "diagram",
diff --git a/songbook.sb b/songbook.sb
index e1fbecc9..dd929c82 100644
--- a/songbook.sb
+++ b/songbook.sb
@@ -1,4 +1,5 @@
 {
-  "template" : "patacrep.tmpl",
-  "songs" : "all"
+"template" : "patacrep.tmpl",
+"lang" : "french",
+"songs" : "all"
 }
diff --git a/utils/header-english b/utils/header-english
index ad4d76d2..297aa71a 100644
--- a/utils/header-english
+++ b/utils/header-english
@@ -1,11 +1,12 @@
 {
 "template" : "patacrep-en.tmpl",
+"lang" : "english",
 "bookoptions" : [
     "diagram",
     "lilypond",
     "pictures"
   ],
 "booktype" : "chorded",
-"subtitle" : "english songs",
+"subtitle" : "English songs",
 "title" : "Guitar Songbook",
 "songs" : [
\ No newline at end of file
diff --git a/utils/header-french b/utils/header-french
index cda63f23..68685567 100644
--- a/utils/header-french
+++ b/utils/header-french
@@ -1,5 +1,6 @@
 {
 "template" : "patacrep.tmpl",
+"lang" : "french",
 "subtitle" : "chanson francaise",
 "bookoptions" : [
     "diagram",
diff --git a/utils/header-volume-3 b/utils/header-volume-3
index 839fdf6d..91f454c4 100644
--- a/utils/header-volume-3
+++ b/utils/header-volume-3
@@ -1,5 +1,6 @@
 {
 "template" : "patacrep.tmpl",
+"lang" : "french",
 "bookoptions" : [
     "diagram",
     "lilypond",
diff --git a/volume-1.sb b/volume-1.sb
index a9cd743e..f867aa7b 100644
--- a/volume-1.sb
+++ b/volume-1.sb
@@ -1,5 +1,6 @@
 {
 "template" : "patacrep.tmpl",
+"lang" : "french",
 "bookoptions" : [
     "diagram",
     "lilypond",
diff --git a/volume-2.sb b/volume-2.sb
index 72a13b2c..d934e8a8 100644
--- a/volume-2.sb
+++ b/volume-2.sb
@@ -1,5 +1,6 @@
 {
 "template" : "patacrep.tmpl",
+"lang" : "french",
 "bookoptions" : [
     "diagram",
     "lilypond",
diff --git a/volume-3.sb b/volume-3.sb
index d67ef022..e916945f 100644
--- a/volume-3.sb
+++ b/volume-3.sb
@@ -1,5 +1,6 @@
 {
 "template" : "patacrep.tmpl",
+"lang" : "french",
 "bookoptions" : [
     "diagram",
     "lilypond",