diff --git a/src/parser.js b/src/parser.js
index <HASH>..<HASH> 100644
--- a/src/parser.js
+++ b/src/parser.js
@@ -463,6 +463,8 @@ class Parser {
         if (_.isFunction(opts)) {
             setter = opts;
             opts = {};
+        } else if (_.isFunction(customHandler)) {
+            setter = customHandler;
         }
 
         const attrs = (opts.list !== undefined)
Allow to use 3rd argument `customHandler` as mentioned in the documentation. (fixes #<I>)