diff --git a/admin/authtypes.pl b/admin/authtypes.pl
index 9f40827029..7be61e012d 100755
--- a/admin/authtypes.pl
+++ b/admin/authtypes.pl
@@ -44,7 +44,7 @@ my ( $template, $borrowernumber, $cookie ) = get_template_and_user(
 
 if ( $op eq 'add_form' ) {
     my $authority_type;
-    if ($authtypecode) {
+    if (defined $authtypecode) {
         $authority_type = Koha::Authority::Types->find($authtypecode);
     }
 
diff --git a/koha-tmpl/intranet-tmpl/prog/en/modules/admin/authtypes.tt b/koha-tmpl/intranet-tmpl/prog/en/modules/admin/authtypes.tt
index 0e899b8eda..4740e4d3b1 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/modules/admin/authtypes.tt
+++ b/koha-tmpl/intranet-tmpl/prog/en/modules/admin/authtypes.tt
@@ -1,7 +1,7 @@
 [% INCLUDE 'doc-head-open.inc' %]
 <title>Koha &rsaquo; Administration &rsaquo; Authority types
 [% IF op == 'add_form' %]
-&rsaquo; [% IF authority_type.authtypecode %]Modify authority type[% ELSE %]New authority type[% END %]
+&rsaquo; [% IF authority_type.authtypecode.defined %]Modify authority type[% ELSE %]New authority type[% END %]
 [% ELSIF op == 'delete_confirm' %]
 &rsaquo; Confirm deletion of authority type
 [% END %]
@@ -32,7 +32,7 @@
 &rsaquo; <a href="/cgi-bin/koha/admin/admin-home.pl">Administration</a>
 &rsaquo; <a href="/cgi-bin/koha/admin/authtypes.pl">Authority types</a>
 [% IF op == 'add_form' %]
-&rsaquo; [% IF authority_type.authtypecode %]Modify[% ELSE %]New[% END %] Authority type
+&rsaquo; [% IF authority_type.authtypecode.defined %]Modify[% ELSE %]New[% END %] Authority type
 [% ELSIF op == 'delete_confirm' %]
 &rsaquo; Confirm deletion of authority type
 [% END %]
@@ -70,7 +70,7 @@
     <form action="/cgi-bin/koha/admin/authtypes.pl" name="Aform" method="post" class="validated">
         <fieldset class="rows">
             <legend>
-                [% IF authority_type.authtypecode %]
+                [% IF authority_type.authtypecode.defined %]
                     Modify authority type
                 [% ELSE %]
                     New authority type
@@ -78,7 +78,7 @@
             </legend>
             <ol>
                 <li>
-                    [% IF authority_type.authtypecode %]
+                    [% IF authority_type.authtypecode.defined %]
                             <span class="label">Authority type</span>
                             <input type="hidden" name="op" value="add_validate" />
                             <input type="hidden" name="checked" value="0" />
@@ -103,7 +103,7 @@
                     <label for="auth_tag_to_report">Authority field to copy: </label>
                     <input type="text" id="auth_tag_to_report" name="auth_tag_to_report" size="5" maxlength="3" value="[% authority_type.auth_tag_to_report %]" />
                     <input type="hidden" name="op" value="add_validate" />
-                    [% IF authority_type.authtypecode %]
+                    [% IF authority_type.authtypecode.defined %]
                         <input type="hidden" name="is_a_modif" value="1" />
                     [% END %]
                 </li>