diff --git a/README.md b/README.md
index 90f7d4e..bb7fe3a 100644
--- a/README.md
+++ b/README.md
@@ -368,6 +368,7 @@ See also [Are we (I)DE yet?](https://areweideyet.com/) and [Rust and IDEs](https
[[testing](https://crates.io/keywords/testing)]
+* [llogiq/mutagen](https://github.com/llogiq/mutagen) [[mutagen](https://crates.io/crates/mutagen)] — A source-level mutation testing framework (nightly only) [](https://travis-ci.org/llogiq/mutagen)
* [AlKass/polish](https://github.com/AlKass/polish) — Mini Testing/Test-Driven Framework [![Build Status](https://api.travis-ci.org/AlKass/polish.svg?branch=master)](https://travis-ci.org/AlKass/polish) [![Crates Package Status](https://img.shields.io/crates/v/polish.svg)](https://crates.io/crates/polish)
* [altsysrq/proptest](https://github.com/altsysrq/proptest) [[proptest](https://crates.io/crates/proptest)] — property testing framework inspired by the [Hypothesis](http://hypothesis.works/) framework for Python [](https://travis-ci.org/altsysrq/proptest)
* [BurntSushi/quickcheck](https://github.com/BurntSushi/quickcheck) [[quickcheck](https://crates.io/crates/quickcheck)] — a Rust implementation of [QuickCheck](https://wiki.haskell.org/Introduction_to_QuickCheck1) [](https://travis-ci.org/BurntSushi/quickcheck)