diff --git a/opam b/opam
index f8e99640a..1092f1011 100644
--- a/opam
+++ b/opam
@@ -34,7 +34,8 @@ depends: [
   "javalib" {>="2.3.3"}
   "ocamlfind" {build}
   "ounit" {="2.0.0"}
-  "reason" {>="1.4.0"}
+  "ppx_deriving" {>="4.1"}
+  "reason" {="1.4.0"}
   "sawja" {>="1.5.2"}
   "xmlm" {>="1.2.0"}
 ]