diff --git a/templates/combo/placeholder.html b/templates/combo/placeholder.html
index 70d492b..970ad9b 100644
--- a/templates/combo/placeholder.html
+++ b/templates/combo/placeholder.html
@@ -1,6 +1,6 @@
 {% load combo %}
 {% for cell in cells %}
-<div class="cell {{ cell.css_class_name }} {% if cell.slug %}{{cell.slug}}{% endif %}"
+<div class="cell {{ cell.css_class_names }} {% if cell.slug %}{{cell.slug}}{% endif %}"
      {% if cell.slug %}id="{{cell.slug}}"{% endif %}
      {% if cell.ajax_refresh %}
      data-ajax-cell-url="{% url 'combo-public-ajax-page-cell' page_pk=page.id cell_reference=cell.get_reference %}"