diff --git a/term_permissions.module b/term_permissions.module
index dee6061..cd449ba 100644
--- a/term_permissions.module
+++ b/term_permissions.module
@@ -112,7 +112,7 @@ function term_permissions_form_alter(&$form, $form_state, $form_id) {
       if (!is_array($vocabulary) || !isset($vocabulary['#options'])) {
         continue;
       }
-      $total_terms = count($vocabulary['#options']) - 1;
+      $total_terms = count($vocabulary['#options']) > 1 ? count($vocabulary['#options']) - 1 : count($vocabulary['#options']);
       foreach($vocabulary['#options'] as $terms) {
         if (!isset($terms->option)) {
           continue;