diff --git a/koha-tmpl/intranet-tmpl/prog/en/includes/doc-head-open.inc b/koha-tmpl/intranet-tmpl/prog/en/includes/doc-head-open.inc
index 8499f3fefa..ea87535446 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/includes/doc-head-open.inc
+++ b/koha-tmpl/intranet-tmpl/prog/en/includes/doc-head-open.inc
@@ -1,4 +1,4 @@
-<!DOCTYPE html PUBLIC "-//W3C//DTD Xhtml 1.0 Transitional//EN"
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
     "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html lang="[% lang %]" xml:lang="[% lang %]" [% IF ( bidi ) %]dir="[% bidi %]"[% END %] xmlns="http://www.w3.org/1999/xhtml">
 <head>
diff --git a/koha-tmpl/opac-tmpl/prog/en/includes/doc-head-open.inc b/koha-tmpl/opac-tmpl/prog/en/includes/doc-head-open.inc
index bbbec2eece..48ec21d300 100644
--- a/koha-tmpl/opac-tmpl/prog/en/includes/doc-head-open.inc
+++ b/koha-tmpl/opac-tmpl/prog/en/includes/doc-head-open.inc
@@ -1,4 +1,4 @@
-<!DOCTYPE html PUBLIC "-//W3C//DTD Xhtml 1.0 Transitional//EN"
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
     "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html lang="[% lang %]" xml:lang="[% lang %]" [% IF ( bidi ) %]dir="[% bidi %]"[% END %] xmlns="http://www.w3.org/1999/xhtml">
 <head>