diff --git a/asli.opam b/asli.opam
index e3b8a4c7..2c87cf31 100644
--- a/asli.opam
+++ b/asli.opam
@@ -19,7 +19,7 @@ depends: [
   "dune" {>= "2.5"}
   "ocaml" {>= "4.09"}
   "menhir" {build}
-  "ott" {build}
+  "ott" {build & >= "0.31"}
   "linenoise"
   "pprint"
   "zarith"
diff --git a/dune-project b/dune-project
index f455adac..f1f07b1b 100644
--- a/dune-project
+++ b/dune-project
@@ -17,7 +17,7 @@
   (depends
     ("ocaml"     (>= "4.09"))
     ("menhir"    :build)
-    ("ott"       :build)
+    ("ott"       (and :build (>= "0.31")))
     "linenoise"
     "pprint"
     "zarith"