diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/includes/masthead-sci.inc b/koha-tmpl/opac-tmpl/bootstrap/en/includes/masthead-sci.inc
index 69f38b1b48..7113136a37 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/includes/masthead-sci.inc
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/includes/masthead-sci.inc
@@ -6,7 +6,7 @@
 [% SET OpacHeader = AdditionalContents.get( location => "opacheader", lang => lang, library => logged_in_user.branchcode || default_branch, blocktitle => 0 ) %]
 
 <div id="wrapper">
-    <div id="header-region" class="noprint">
+    <header id="header-region" class="noprint">
         <nav class="navbar navbar-expand">
             <h1 id="logo">
                 <a class="navbar-brand" href="/cgi-bin/koha/sci/sci-main.pl">
@@ -44,6 +44,6 @@
                 </div>
             </div>
         [% END # /IF opacheader %]
-    </div>
+    </header>
     <!-- /navbar -->
 </div>
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/includes/masthead-sco.inc b/koha-tmpl/opac-tmpl/bootstrap/en/includes/masthead-sco.inc
index 9faafaa507..624dcc4b19 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/includes/masthead-sco.inc
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/includes/masthead-sco.inc
@@ -5,7 +5,7 @@
 [% SET OpacLangSelectorMode = Koha.Preference('OpacLangSelectorMode') %]
 [% SET OpacHeader = AdditionalContents.get( location => "opacheader", lang => lang, library => logged_in_user.branchcode || default_branch, blocktitle => 0 ) %]
 
-<div id="header-region" class="noprint">
+<header id="header-region" class="noprint">
     <nav class="navbar navbar-expand">
         <h1 id="logo">
             <a class="navbar-brand" href="/cgi-bin/koha/sco/sco-main.pl">
@@ -40,5 +40,5 @@
             </div>
         </div>
     [% END # /IF opacheader %]
-</div>
+</header>
 <!-- /navbar -->
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/modules/errors/errorpage.tt b/koha-tmpl/opac-tmpl/bootstrap/en/modules/errors/errorpage.tt
index 9884f163e4..46ced64f57 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/modules/errors/errorpage.tt
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/modules/errors/errorpage.tt
@@ -18,7 +18,7 @@
 <body id="error[% errno | html %]" class="error">
 [% INCLUDE 'masthead.inc' %]
 
-<div class="main">
+<main class="main">
     [% WRAPPER breadcrumbs %]
         [% WRAPPER breadcrumb_item bc_active = 1 %]
             <span>An error has occurred</span>
@@ -97,7 +97,7 @@
         <!-- / .row -->
     </div>
     <!-- / .container-fluid -->
-</div>
+</main>
 <!-- / .main -->
 
 [% INCLUDE 'opac-bottom.inc' %]
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/modules/maintenance.tt b/koha-tmpl/opac-tmpl/bootstrap/en/modules/maintenance.tt
index 5aa6697cf1..223c072202 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/modules/maintenance.tt
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/modules/maintenance.tt
@@ -40,7 +40,7 @@
 </head>
 <body id="opac_maintenance" class="opac">
 <div id="wrapper">
-    <div id="header-region" class="noprint">
+    <header id="header-region" class="noprint">
         <nav class="navbar navbar-expand">
             <div id="logo">
                 <a class="navbar-brand" href="/cgi-bin/koha/opac-main.pl">
@@ -56,7 +56,7 @@
                 [% INCLUDE 'langmenu.inc' %]
             [% END %]
         </nav>
-    </div>
+    </header>
 
     [% IF ( OpacHeader ) %]
         <div class="container-fluid">
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-illrequests_unauthenticated.tt b/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-illrequests_unauthenticated.tt
index 95524484e4..e66e68f342 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-illrequests_unauthenticated.tt
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-illrequests_unauthenticated.tt
@@ -11,7 +11,7 @@
 [% INCLUDE 'bodytag.inc' bodyid='opac-illrequests' %]
 
 [% INCLUDE 'masthead.inc' %]
-<div class="main">
+<main class="main">
     [% WRAPPER breadcrumbs %]
         [% IF op != 'list' %]
             [% WRAPPER breadcrumb_item %]
@@ -107,7 +107,7 @@
             </div>
         </div>
     </div>
-</div>
+</main>
 
 [% INCLUDE 'opac-bottom.inc' %]
 
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/modules/sci/sci-main.tt b/koha-tmpl/opac-tmpl/bootstrap/en/modules/sci/sci-main.tt
index 1a6330580a..1f9664fc3d 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/modules/sci/sci-main.tt
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/modules/sci/sci-main.tt
@@ -76,7 +76,7 @@
 <body id="sci_main" class="sci">
 [% INCLUDE 'masthead-sci.inc' %]
 
-<div class="main">
+<main class="main">
     <div class="container-fluid">
         <div class="row">
             <div class="col order-first order-md-first order-lg-2">
@@ -186,7 +186,7 @@
         <!-- / .row -->
     </div>
     <!-- / .container-fluid -->
-</div>
+</main>
 <!-- / .main -->
 
 [% # Help modal %]
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/modules/sco/help.tt b/koha-tmpl/opac-tmpl/bootstrap/en/modules/sco/help.tt
index 918f78442b..bbfdb49ef1 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/modules/sco/help.tt
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/modules/sco/help.tt
@@ -48,7 +48,7 @@
 <div id="wrapper">
     [% INCLUDE 'masthead-sco.inc' %]
 
-    <div class="main">
+    <main class="main">
         <div class="container-fluid">
             <div class="row">
                 <div class="col order-first order-md-first order-lg-2">
@@ -86,7 +86,7 @@
             <!-- / .row -->
         </div>
         <!-- / .container-fluid -->
-    </div>
+    </main>
     <!-- / .main -->
 </div>
 
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/modules/sco/sco-main.tt b/koha-tmpl/opac-tmpl/bootstrap/en/modules/sco/sco-main.tt
index 486b442fcd..2fa0a7925b 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/modules/sco/sco-main.tt
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/modules/sco/sco-main.tt
@@ -61,7 +61,7 @@
 <div id="wrapper">
     [% INCLUDE 'masthead-sco.inc' %]
 
-    <div class="main">
+    <main class="main">
         [% IF ( display_patron_image ) %]
             [% SET main_div_class = 'col-10 order-first order-md-first order-lg-2' %]
         [% ELSE %]
@@ -398,7 +398,7 @@
             </div>
             <!-- / .container-fluid -->
         [% END # / UNLESS ( hide_main %]
-    </div>
+    </main>
     <!-- / .main -->
     <span id="audio-alert"></span>
 
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/modules/svc/suggestion.tt b/koha-tmpl/opac-tmpl/bootstrap/en/modules/svc/suggestion.tt
index a234936b08..66c39459cd 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/modules/svc/suggestion.tt
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/modules/svc/suggestion.tt
@@ -26,7 +26,7 @@
     <body id="opac-suggestion" class="opac">
     [% INCLUDE 'masthead.inc' %]
 
-    <div class="main">
+    <main class="main">
         [% WRAPPER breadcrumbs %]
             [% WRAPPER breadcrumb_item bc_active= 1 %]
                 <span>Search suggestions</span>
@@ -56,7 +56,7 @@
             <!-- / .row -->
         </div>
         <!-- / .container-fluid -->
-    </div>
+    </main>
     <!-- / .main -->
     [% INCLUDE 'opac-bottom.inc' %]
     [% BLOCK jsinclude %]