diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 76d26db9c8117ae52965102cf26b1e5e74ae47e5..ef1d35d537c9bb71428390c55a0e8c0096b0e784 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -26,9 +26,7 @@ build:
     - opam repo add official "https://opam.ocaml.org/"
     - opam repo add verimag-sync-repo "http://www-verimag.imag.fr/DIST-TOOLS/SYNCHRONE/test/opam-repository"
     - opam update
-    - opam install -y ocamlfind dune extlib depext
-    - opam depext -y rdbg
-    - opam install rdbg 
+    - opam install --deps-only ./lustre-v6.opam
     - make
     - make install
 
diff --git a/lustre-v6.opam b/lustre-v6.opam
index 3c7d7e2f14e06d8f066edbacab6710032f5d5d7a..6d8febcc5f06a92527f24d55af73487f7a4af98f 100644
--- a/lustre-v6.opam
+++ b/lustre-v6.opam
@@ -19,7 +19,8 @@ depends: [
   "ocamlfind"
   "lutils" {>= "1.49"}
   "rdbg" {>= "1.196.9"}
-  "num" 
+  "num"
+  "yaml"
 ]
 build: ["dune" "build" "-p" name "-j" jobs]
 post-messages: