diff --git a/catala.opam b/catala.opam
index a98e0124..37d8f075 100644
--- a/catala.opam
+++ b/catala.opam
@@ -53,6 +53,7 @@ depends: [
 depopts: ["z3"]
 conflicts: [
   "z3" {< "4.8.11"}
+  "base" {>= "v0.16.0"}
 ]
 build: [
   ["dune" "subst"] {dev}