diff --git a/fusion_core/theme-settings.php b/fusion_core/theme-settings.php
index ec69ade945b16b1aa105671b6e33bc1a73625229..db32b4140d524a734d8af53d25363a8c2593f87e 100644
--- a/fusion_core/theme-settings.php
+++ b/fusion_core/theme-settings.php
@@ -19,8 +19,8 @@
 function fusion_core_form_system_theme_settings_alter(&$form, $form_state) {
   global $base_url;
 
-  // Get theme name from url (admin/.../theme_name)
-  $theme_name = arg(count(arg()) - 1);
+  // Get theme name from $form_state.
+  $theme_name = $form_state['build_info']['args'][0];
 
   // Get default theme settings from .info file
   $theme_data = list_themes();   // get data for all themes