diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index b32ff5491912..5c1aad3520cb 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -9830,7 +9830,9 @@ with pkgs;
 
   skippy-xd = callPackage ../tools/X11/skippy-xd {};
 
-  sks = callPackage ../servers/sks { };
+  sks = callPackage ../servers/sks {
+    ocamlPackages = ocaml-ng.ocamlPackages_4_12;
+  };
 
   skydns = callPackage ../servers/skydns { };