diff --git a/sites/all/modules/block_class/block_class.module b/sites/all/modules/block_class/block_class.module
index c16dde0..d33f62b 100644
--- a/sites/all/modules/block_class/block_class.module
+++ b/sites/all/modules/block_class/block_class.module
@@ -84,6 +84,12 @@ function block_class_form_submit($form, &$form_state) {
       $delta = $form_state['values']['delta'];
       $class = $form_state['values']['css_class'];
 
+      //$delta is null if this is the add block form
+      if ($form_state['values']['form_id'] == 'block_add_block_form') {
+        $lastBlock = db_last_insert_id('blocks', 'bid');
+        $delta = db_result(db_query('SELECT delta FROM {blocks} WHERE bid = %d', array($lastBlock)));
+      }
+
       db_query("DELETE FROM {block_class} WHERE module = '%s' AND delta = '%s'", $module, $delta);
 
       if (!empty($class)) {