diff --git a/public/src/forum/admin/themes.js b/public/src/forum/admin/themes.js
index 78328a6027..6207b98fff 100644
--- a/public/src/forum/admin/themes.js
+++ b/public/src/forum/admin/themes.js
@@ -155,6 +155,7 @@ define(['forum/admin/settings'], function(Settings) {
 			if (!el.hasClass('block')) {
 				el.addClass('block')
 					.droppable({
+						accept: '[data-container-html]',
 						drop: function(event, ui) {
 							var el = $(this);