diff --git a/src/stdune/sexp.ml b/src/stdune/sexp.ml
index a23e3a6b..4eef7da0 100644
--- a/src/stdune/sexp.ml
+++ b/src/stdune/sexp.ml
@@ -91,12 +91,12 @@ module Of_sexp = struct
 
     type error = string * hint option
 
-    let error ?hint str = Error (str, hint)
+    let error ?hint str = Result.Error (str, hint)
     let errorf ?hint fmt = Printf.ksprintf (error ?hint) fmt
 
     let map_validate t ~f ast =
       match f (t ast) with
-      | Ok b -> b
+      | Result.Ok b -> b
       | Error (msg, hint) -> raise (Of_sexp (Ast.loc ast, msg, hint))
   end
 
diff --git a/src/stdune/sexp.mli b/src/stdune/sexp.mli
index 417484ed..b78d23ea 100644
--- a/src/stdune/sexp.mli
+++ b/src/stdune/sexp.mli
@@ -87,7 +87,7 @@ module Of_sexp : sig
 
     val error : ?hint:hint -> string -> (_, error) Result.t
     val errorf
-      : ?hint:hint -> ('b, unit, string, (_, error) result) format4 -> 'b
+      : ?hint:hint -> ('b, unit, string, (_, error) Result.t) format4 -> 'b
     val map_validate : 'a t -> f:('a -> ('b, error) Result.t) -> 'b t
   end