diff --git a/README.md b/README.md
index 94138e1d..37715c60 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@ HTML Purifier [![Build Status](https://secure.travis-ci.org/ezyang/htmlpurifier.
 =============
 
 HTML Purifier is an HTML filtering solution that uses a unique combination
-of robust whitelists and agressive parsing to ensure that not only are
+of robust whitelists and aggressive parsing to ensure that not only are
 XSS attacks thwarted, but the resulting HTML is standards compliant.
 
 HTML Purifier is oriented towards richly formatted documents from