diff --git a/README.md b/README.md
index 74d618ed2fea7c95e5034e330662d2b1e409a7f4..03a5bc8af0911305d7f019b63479bf83d1353b2b 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ can coexist on the same system.
 Most importantly, Spack is simple. It offers a simple spec syntax so
 that users can specify versions and configuration options
 concisely. Spack is also simple for package authors: package files are
-writtin in pure Python, and specs allow package authors to write a
+written in pure Python, and specs allow package authors to write a
 single build script for many different builds of the same package.
 
 See the