diff --git a/README.md b/README.md
index 0736d716..9f0dacc8 100644
--- a/README.md
+++ b/README.md
@@ -154,8 +154,7 @@ https://github.com/wasabiz/picrin
 
 picrin scheme depends on some external libraries to build the binary:
 
-- bison
-- yacc
+- lex (preferably, flex)
 - make
 - gcc
 - readline