diff --git a/lib/compilers.js b/lib/compilers.js
index <HASH>..<HASH> 100644
--- a/lib/compilers.js
+++ b/lib/compilers.js
@@ -147,7 +147,7 @@ function generateFootnotes() {
  * @this {HTMLCompiler}
  */
 function unknown(node) {
-    var content = 'children' in node ? this.all(node) : node.value;
+    var content = 'children' in node ? this.all(node).join('') : node.value;
 
     return h(this, node, {
         'name': 'div',
Fix output of unknown node with multiple children

HTML output for unknown nodes are separated by commas. Fix by
converting the content value to a string prior to stringification.

Closes GH-5.

Closes GH-6.