diff --git a/about.pl b/about.pl
index ba77ca6d44..4687a45a3b 100755
--- a/about.pl
+++ b/about.pl
@@ -78,6 +78,19 @@ my $errZebraConnection = C4::Context->Zconn("biblioserver",0)->errcode();
 my $warnIsRootUser   = (! $loggedinuser);
 
 my $warnNoActiveCurrency = (! defined C4::Budgets->GetCurrency());
+my @xml_config_warnings;
+
+if ( ! defined C4::Context->config('zebra_bib_index_mode') ) {
+    push @xml_config_warnings, {
+        error => 'zebra_bib_index_mode_warn'
+    };
+}
+
+if ( ! defined C4::Context->config('zebra_auth_index_mode') ) {
+    push @xml_config_warnings, {
+        error => 'zebra_auth_index_mode_warn'
+    };
+}
 
 $template->param(
     kohaVersion   => $kohaVersion,
@@ -96,6 +109,7 @@ $template->param(
     errZebraConnection => $errZebraConnection,
     warnIsRootUser => $warnIsRootUser,
     warnNoActiveCurrency => $warnNoActiveCurrency,
+    xml_config_warnings => \@xml_config_warnings,
 );
 
 my @components = ();
diff --git a/koha-tmpl/intranet-tmpl/prog/en/modules/about.tt b/koha-tmpl/intranet-tmpl/prog/en/modules/about.tt
index 90f92bb32f..1477b02258 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/modules/about.tt
+++ b/koha-tmpl/intranet-tmpl/prog/en/modules/about.tt
@@ -120,6 +120,17 @@
                 <tr><th scope="row"><b>Warning</b> </th><td>No active currency is defined. Please go to <a href="/cgi-bin/koha/admin/currency.pl">Administration &gt; Currencies and exchange rates</a> and mark one currency as active.</td></tr>
             [% END %]
         </table>
+        [% ELSIF xml_config_warnings.size %]
+        <table>
+            <caption>XML configuration file</caption>
+        [% FOREACH config_entry IN xml_config_warnings %]
+            [% IF config_entry.error == 'zebra_bib_index_mode_warn' %]
+            <tr><th scope="row"><b>Warning</b> </th><td>The &lt;zebra_bib_index_mode&gt; entry is missing in your configuration file. It should be set to <strong>dom</strong> or <strong>grs1</strong>. It will default to <strong>grs1</strong> but this could change in the future.</td></tr>
+            [% ELSIF config_entry.error == 'zebra_auth_index_mode_warn' %]
+            <tr><th scope="row"><b>Warning</b> </th><td>The &lt;zebra_auth_index_mode&gt; entry is missing in your configuration file. It should be set to <strong>dom</strong> or <strong>grs1</strong>. It will default to <strong>dom</strong> but this could change in the future.</td></tr>
+            [% END %]
+        [% END %]
+        </table>
         [% ELSE %]
             <p>No warnings</p>
         [% END %]