diff --git a/extra/lisp/lisp.factor b/extra/lisp/lisp.factor
index c604a35b1b..e051241a32 100644
--- a/extra/lisp/lisp.factor
+++ b/extra/lisp/lisp.factor
@@ -1,4 +1,8 @@
 ! Copyright (C) 2008 James Cash
 ! See http://factorcode.org/license.txt for BSD license.
+USING: kernel peg.ebnf peg.expr ;
+IN: lisp
 
-IN: lisp
\ No newline at end of file
+EBNF: expr
+list  = "(" ( atom | list )* ")"   =>  [[ second 1array ]]
+;EBNF
\ No newline at end of file