diff --git a/README b/README
index 83e2f2d..34a9efb 100644
--- a/README
+++ b/README
@@ -31,7 +31,7 @@ shell environment by running: eval $(opam config env)
 
 [2] Install dependencies using OPAM
 
-opam install batteries twt gsl-ocaml
+opam install batteries ocaml+twt gsl-ocaml
 
 The gsl-ocaml package may require you to separately install the GNU Scientific
 Library (GSL) from: http://www.gnu.org/software/gsl/