diff --git a/feat-core.opam b/feat-core.opam
index 0b58a575d844712a7a355e9f031664555e82739b..29757c85bf0ec946848f3eae9efb036b71d16e11 100644
--- a/feat-core.opam
+++ b/feat-core.opam
@@ -14,6 +14,6 @@ depends: [
   "ocaml" { >= "4.03" }
   "dune" { >= "1.3" }
   "seq"
-  "fix" { >= "20181206" }
+  "fix" { >= "20201120" }
 ]
 synopsis: "Facilities for enumerating and sampling algebraic data types"