diff --git a/src/posts/summary.js b/src/posts/summary.js
index 32651b67c1..a245a41b29 100644
--- a/src/posts/summary.js
+++ b/src/posts/summary.js
@@ -86,7 +86,7 @@ module.exports = function(Posts) {
 						if (options.stripTags) {
 							post.content = stripTags(post.content);
 						}
-						post.content = post.content ? validator.escape(post.content) : post.content;
+						post.content = post.content ? validator.escape(String(post.content)) : post.content;
 						return next(null, post);
 					}