<!-- STOP AND READ THIS BEFORE POSTING YOUR ISSUE --- Have a general question? --- First check out the Docs: https://facebook.github.io/immutable-js/docs/ And check out the Wiki: https://github.com/facebook/immutable-js/wiki/ Search existing issues: https://github.com/facebook/immutable-js/search?type=Issues&q=question Ask on Stack Overflow!: https://stackoverflow.com/questions/tagged/immutable.js?sort=votes * Stack Overflow gets more attention * Answered questions are searchable * A whole community can answer --- Feature request? --- This library attempts to be as stable as possible so features have to meet a high bar to be added. This library also prefers interoperability with other libraries over continuous additions. Here are some tips to get your feature added: * Search existing issues and pull requests first. * Send a Pull Request! Start with API design and post for review early. --- Found a bug? --- Search existing issues first: https://github.com/facebook/immutable-js/search?type=Issues&q=bug Please ensure you're using the latest version, and provide some information below. --> ### What happened mergeWith working fine as per https://immutable-js.github.io/immutable-js/docs/#/mergeWith docs. mergeDeepWith NOT working fine as per https://immutable-js.github.io/immutable-js/docs/#/mergeDeepWith. It says like mergeDeepWith is recursive implementation of mergeWith. @leebyron Isn't it? ### How to reproduce <img width="1680" alt="Screen Shot 2020-07-07 at 12 05 50 PM" src="https://user-images.githubusercontent.com/17532117/86729220-dc0a5900-c04a-11ea-9e4f-3fedf3985975.png">