diff --git a/README.md b/README.md
index f6049421..6ef951bb 100644
--- a/README.md
+++ b/README.md
@@ -36,8 +36,9 @@ Used by:
 
 - [SciPy](https://github.com/scipy/scipy) — Fundamental algorithms for
   scientific computing.
-- [scikit-learn](https://github.com/scikit-learn/scikit-learn) — Machine
+- [scikit-learn](https://github.com/scikit-learn/scikit-learn) — Machine
   Learning in Python.
+- [SysIdentPy](https://github.com/wilsonrljr/sysidentpy) — System Identification Using NARMAX Models.
 - *your library? Let us know!*
 
 ## Installation
diff --git a/docs/index.md b/docs/index.md
index 5168e973..29e2ed08 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -27,6 +27,7 @@ It is currently used by:
   scientific computing.
 - [scikit-learn](https://github.com/scikit-learn/scikit-learn) — Machine
   Learning in Python.
+- [SysIdentPy](https://github.com/wilsonrljr/sysidentpy) — System Identification Using NARMAX Models.
 - *your library? Let us know!*
 
 (installation)=