diff --git a/hosts/ocaml/bin/sx_server.ml b/hosts/ocaml/bin/sx_server.ml
index f86b573b..0b168dac 100644
--- a/hosts/ocaml/bin/sx_server.ml
+++ b/hosts/ocaml/bin/sx_server.ml
@@ -728,6 +728,8 @@ let register_jit_hook env =
        | Some _ -> None  (* compile failed or disabled — CEK handles *)
        | None ->
          if !_jit_compiling then None
+         else if Hashtbl.mem _jit_warned fn_name then
+           (l.l_compiled <- Some Sx_vm.jit_failed_sentinel; None)
          else begin
            _jit_compiling := true;
            let t0 = Unix.gettimeofday () in