diff --git a/extra/io/nonblocking/nonblocking-docs.factor b/extra/io/nonblocking/nonblocking-docs.factor
index d0d5818bee..d6d619229f 100644
--- a/extra/io/nonblocking/nonblocking-docs.factor
+++ b/extra/io/nonblocking/nonblocking-docs.factor
@@ -1,5 +1,5 @@
 USING: io io.buffers io.backend help.markup help.syntax kernel
-strings sbufs ;
+strings sbufs words ;
 IN: io.nonblocking
 
 ARTICLE: "io.nonblocking" "Non-blocking I/O implementation"