diff --git a/contrib/README.txt b/contrib/README.txt
index add3039c05..83ae59dde6 100644
--- a/contrib/README.txt
+++ b/contrib/README.txt
@@ -33,3 +33,5 @@ library, but is useful enough to ship with the Factor distribution.
 - contrib/dlists.factor -- double-linked-lists (Mackenzie Straight)
 
 - contrib/xml.factor -- XML parser and writer (Daniel Ehrenberg)
+
+- contrib/x11 -- X Window System client library (Eduardo Cavazos)
\ No newline at end of file