diff --git a/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/2F/Register/TOTP.pm b/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/2F/Register/TOTP.pm
index bdf82b429..3831c003a 100644
--- a/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/2F/Register/TOTP.pm
+++ b/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/2F/Register/TOTP.pm
@@ -171,7 +171,7 @@ sub run {
         $self->p->updatePersistentSession( $req,
             { _2fDevices => to_json( \@keep ) } );
         $self->userLogger->notice('TOTP registration succeed');
-        return [ 200, [ 'Content-Type' => 'application/json' ],
+        return [ 200, [ 'Content-Type' => 'application/json', 'Content-Length' => 12, ],
             ['{"result":1}'] ];
     }
 
@@ -304,7 +304,7 @@ sub run {
         $self->p->updatePersistentSession( $req,
             { _2fDevices => to_json( \@keep ) } );
         $self->userLogger->notice('TOTP deletion succeed');
-        return [ 200, [ 'Content-Type' => 'application/json' ],
+        return [ 200, [ 'Content-Type' => 'application/json', 'Content-Length' => 12, ],
             ['{"result":1}'] ];
     }
 }
diff --git a/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/2F/Register/U2F.pm b/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/2F/Register/U2F.pm
index 609b17b67..bf43075ad 100644
--- a/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/2F/Register/U2F.pm
+++ b/lemonldap-ng-portal/lib/Lemonldap/NG/Portal/2F/Register/U2F.pm
@@ -70,7 +70,7 @@ sub run {
             ],
             [$challenge]
         ];
-        return [ 200, [ 'Content-Type' => 'application/json' ], [$challenge] ];
+        # return twice ??? return [ 200, [ 'Content-Type' => 'application/json' ], [$challenge] ];
     }
     if ( $action eq 'registration' ) {
         my ( $resp, $challenge );