diff --git a/Makefile b/Makefile
index 1f8914c8..7a091109 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@
 LOG=build.log
 COMP=ocamlbuild -log $(LOG) -use-ocamlfind -package num,zarith,unix -classic-display
 FLAGS=
-DIRS=-Is smt,common
+DIRS=-Is sat,smt,common
 DOC=msat.docdir/index.html
 
 NAME=msat
diff --git a/README.md b/README.md
index 0dcd0fac..fc46d9b0 100644
--- a/README.md
+++ b/README.md
@@ -19,8 +19,17 @@ This program is distributed under the Apache Software License version
 
 
 ## INSTALLATION
-============
 
-You will need ocamlfind.
+### Via opam
+
+Once the package is on [opam](http://opam.ocaml.org), just `opam install msat`.
+For the development version, use:
+
+    opam pin add msat https://github.com/Gbury/mSAT.git
+
+### Manual installation You will need ocamlfind. The command is:
+
+    make install
+
 
 
diff --git a/sat/solver.ml b/sat/solver.ml
index b1e0b45c..474dfd6b 100644
--- a/sat/solver.ml
+++ b/sat/solver.ml
@@ -14,7 +14,7 @@ open Format
 
 module Make(F : Formula_intf.S)(Th : Theory_intf.S with type formula = F.t) = struct
 
-module Stypes =  Solver_types.Make(F)
+module Stypes = Solver_types.Make(F)
 module Ex = Explanation.Make(Stypes)
 
 open Stypes
@@ -23,8 +23,6 @@ exception Sat
 exception Unsat of clause list
 exception Restart
 
-
-
 type env =
     {
         (* si vrai, les contraintes sont deja fausses *)