diff --git a/Bugzilla/WebService/Field.pm b/Bugzilla/WebService/Field.pm
index 75720369b..66fc8d04d 100644
--- a/Bugzilla/WebService/Field.pm
+++ b/Bugzilla/WebService/Field.pm
@@ -86,9 +86,12 @@ sub update_value
         {
             return {status => 'value_already_exists'};
         }
+        $value->set_value($params->{new_value});
+    }
+    if (exists $params->{sortkey})
+    {
+        $value->set_sortkey($params->{sortkey});
     }
-    $value->set_value($params->{new_value});
-    $value->set_sortkey($params->{sortkey});
     $value->update;
     return {status => 'ok', id => $value->id};
 }