diff --git a/handlers/views_handler_filter_dynamic_fields.inc b/handlers/views_handler_filter_dynamic_fields.inc
index db5b243..ab2f4f3 100755
--- a/handlers/views_handler_filter_dynamic_fields.inc
+++ b/handlers/views_handler_filter_dynamic_fields.inc
@@ -63,7 +63,7 @@ class views_handler_filter_dynamic_fields extends views_handler_filter {
     $style_columns = isset($view->display_handler->default_display->options['style_options']['columns']) ? $view->display_handler->default_display->options['style_options']['columns'] : NULL;
     if (is_array($style_columns)) {
       foreach ($style_columns as $key => $name) {
-        if ($this->view_fields[$key] && $key != $name) {
+        if (isset($this->view_fields[$key]) && $key != $name) {
           unset($this->view_fields[$key]);
           // The $key field will be acted upon if the $name (parent) field is acted upon by the user
           $this->combined_fields[$name] = $key;