diff --git a/doc/ack.xml b/doc/ack.xml
index 2223336..0459fde 100644
--- a/doc/ack.xml
+++ b/doc/ack.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" ?>
 <!-- $Id$ -->
 <notes>
-The following individuals have constributed useful comments and code.
+The following individuals have contributed useful comments and code.
 UMLGraph would not be in its current state without their contributions.
 <ul>
 <li>Nascif Abousalh-Neto</li>