diff --git a/nix/packages/necrolib.nix b/nix/packages/necrolib.nix
index a9b20e2d..3c85c9a5 100644
--- a/nix/packages/necrolib.nix
+++ b/nix/packages/necrolib.nix
@@ -1,7 +1,7 @@
 {
   fetchFromGitLab,
   ocaml-ng,
-  ocamlPackages ? ocaml-ng.ocamlPackages_4_14,
+  ocamlPackages ? ocaml-ng.ocamlPackages_5_1,
 }: let
   version = "v0.16.2";
 in
@@ -9,7 +9,7 @@ in
     pname = "necrolib";
     inherit version;
 
-    minimalOCamlVersion = "4.14.1";
+    minimalOCamlVersion = "5.1.1";
 
     src = fetchFromGitLab {
       domain = "gitlab.inria.fr";