diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index 1d42dbc96d7..6ae5f43a63c 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -1502,5 +1502,5 @@ in let inherit (pkgs) callPackage; in rec
 
   ocamlPackages_latest = ocamlPackages_4_12;
 
-  ocamlPackages = ocamlPackages_4_10;
+  ocamlPackages = ocamlPackages_4_12;
 }