diff --git a/m4/ac_assert_ocaml_pkg.m4 b/m4/ac_assert_ocaml_pkg.m4
index b14fab3b8..84c0b080f 100644
--- a/m4/ac_assert_ocaml_pkg.m4
+++ b/m4/ac_assert_ocaml_pkg.m4
@@ -19,17 +19,18 @@ AC_DEFUN([AC_ASSERT_OCAML_PKG],
   has_pkg=$AS_TR_SH[OCAML_PKG_$1]
   AS_IF([test "$has_pkg" = "no"],
   [dnl
-    unset version
-    unset version_msg
+   unset opam_command
+   unset version
+    opam_command="opam pin add $1 $3"
     version=".$3"
-    AS_IF([test "x$3" = "x"], [version=""])
-    version_msg=""
-    AS_IF([test "x$3" != "x"], [version_msg=" version $3"])
-    AC_MSG_ERROR([missing dependency: $1$version_msg.
+    AS_IF([test "x$3" = "x"],
+      [opam_command="opam install $1"
+      version=""])
+    AC_MSG_ERROR([missing dependency: $1$version.
 
 If you are using opam, please run
 
-  opam install $1$version])
+  $opam_command])
   ])
 ])
 
diff --git a/opam b/opam
index dc5ddaf69..bfb071e0e 100644
--- a/opam
+++ b/opam
@@ -1,24 +1,27 @@
 opam-version: "1.2"
 name: "infer"
-version: "0.1.0"
+version: "0.4.0"
 maintainer: "opam-devel@lists.ocaml.org"
 authors: "Facebook"
 homepage: "https://github.com/facebook/infer"
 bug-reports: "https://github.com/facebook/infer/issues"
 dev-repo: "https://github.com/facebook/infer.git"
 license: "BSD"
-build: [ [make "-C" "infer" "java"] ]
+build: [
+  ["./autogen.sh"]
+  ["./configure"]
+  [make "infer" "java"]
+]
 install: []
 remove: []
 depends: [
   "ocamlfind" {build}
-  "sawja" {>="1.5.1"}
-  "atdgen" {>="1.6"}
-  "javalib" {>="2.3.1"}
-  "extlib" {>="1.5.4"}
+  "sawja" {="1.5.1"}
+  "atdgen" {="1.6.0"}
+  "javalib" {="2.3.1"}
+  "extlib" {="1.5.4"}
 ]
 depexts: [
   [ ["ubuntu"] ["python2.7-dev"] ]
   [ ["debian"] ["python2.7-dev"] ]
 ]
-