diff --git a/README.md b/README.md
index 9974c5bb..f51a5a73 100644
--- a/README.md
+++ b/README.md
@@ -164,6 +164,7 @@ https://github.com/wasabiz/picrin
 picrin scheme depends on some external libraries to build the binary:
 
 - lex (preferably, flex)
+- getopt
 - readline (optional)
 
 The compilation is tested only on Mac OSX and Ubuntu. I think (or hope) it'll be ok to compile and run on other operating systems such as Arch or Windows, but I don't guarantee :(