diff --git a/Makefile b/Makefile
index e62f57e40eadb3132094502119e1264bfbdf2435..e20217a868d6ae0e3da6e5864e8a83ec72537b19 100644
--- a/Makefile
+++ b/Makefile
@@ -25,7 +25,7 @@ man:
 
 ###############################
 # for developpers
-include ./Makefile.dev
+-include ./Makefile.dev
 
 # not gitted stuff
 -include ./Makefile.local
diff --git a/Makefile.dev b/Makefile.dev
index b0ffcde9436ac3c109a8371162e62b7c6f930607..47092834b30606db4beb2802da20388c2c35f75e 100644
--- a/Makefile.dev
+++ b/Makefile.dev
@@ -62,12 +62,16 @@ amend:
 # opam-ing
 
 NAME=lustre-v6
+SRC=lib bin LICENSE Makefile Makefile.version *.opam
 
-opam-rel :
-	make-opam-pack $(NAME)
+$(NAME).$(VERSION).tgz: $(SRC) 
+	git archive --prefix=$(NAME).$(VERSION)/ -o $@ HEAD $(SRC) test
 
-opam-test :
-	make-opam-pack $(NAME) -test
+opam-rel : $(NAME).$(VERSION).tgz
+	make-opam-pack $(NAME).$(VERSION) $(NAME)
+
+opam-test : $(NAME).$(VERSION).tgz
+	make-opam-pack $(NAME).$(VERSION) $(NAME) -test