diff --git a/README.md b/README.md
index 5b5fddf2..2c886ec6 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@
 [![Build Status](https://travis-ci.org/picrin-scheme/picrin.png?branch=master)](https://travis-ci.org/picrin-scheme/picrin)
 [![Docs Status](https://readthedocs.org/projects/picrin/badge/?version=latest)](https://picrin.readthedocs.org/)
 
-Picrin is a lightweight R7RS scheme implementation written in pure C89. It contains a reasonably fast VM, an improved hygienic macro system, usuful contribution libraries, and simple but powerful C interface.
+Picrin is a lightweight R7RS scheme implementation written in pure C89. It contains a reasonably fast VM, an improved hygienic macro system, useful contribution libraries, and simple but powerful C interface.
 
 - R7RS compatible
 - Reentrant design (all VM states are stored in single global state object)