diff --git a/dune-project b/dune-project
index ccd812b44..4f73ec941 100644
--- a/dune-project
+++ b/dune-project
@@ -63,5 +63,5 @@ the Why3 platform.")
   (yojson (>= 1.6.0))
   (cmdliner (>= 1.1.0))
   (stdlib-shims (>= 0.1.0))
-  lwt_ppx
-  dream))
+  (lwt_ppx (>= 1.0.0))
+  (dream (>= 1.0.0~alpha1))))
diff --git a/lambdapi.opam b/lambdapi.opam
index 256e40cfa..e7de2dcc6 100644
--- a/lambdapi.opam
+++ b/lambdapi.opam
@@ -62,8 +62,8 @@ depends: [
   "cmdliner" {>= "1.1.0"}
   "stdlib-shims" {>= "0.1.0"}
   "odoc" {with-doc}
-  "dream"
-  "lwt_ppx"
+  "dream" {>= "1.0.0~alpha1"}
+  "lwt_ppx" {>= "1.0.0"}
 ]
 build: [
   ["dune" "subst"] {dev}