diff --git a/ocaml/lib/pickles_bindings.ml b/ocaml/lib/pickles_bindings.ml
index aaacacc6..742cd6d6 100644
--- a/ocaml/lib/pickles_bindings.ml
+++ b/ocaml/lib/pickles_bindings.ml
@@ -29,6 +29,8 @@ let public_input_typ (i : int) = Typ.array ~length:i Field.typ
 let statement_typ (input_size : int) (output_size : int) =
   Typ.(array ~length:input_size Field.typ * array ~length:output_size Field.typ)
 
+type proof = (Pickles_types.Nat.N0.n, Pickles_types.Nat.N0.n) Pickles.Proof.t
+
 type ('prev_proof, 'proof) js_prover =
      Public_input.Constant.t
   -> 'prev_proof array
@@ -74,7 +76,8 @@ type pickles_rule_js =
   ; proofsToVerify :
       < isSelf : bool Js.t Js.prop ; tag : Js.Unsafe.any Js.t Js.prop > Js.t
       array
-      Js.prop >
+      Js.prop 
+  ; previousProofs : proof array Js.prop >
   Js.t
 
 module Choices = struct
diff --git a/ocaml/lib/pickles_bindings.mli b/ocaml/lib/pickles_bindings.mli
index d8207647..eb5f6f8b 100644
--- a/ocaml/lib/pickles_bindings.mli
+++ b/ocaml/lib/pickles_bindings.mli
@@ -21,6 +21,8 @@ module Statement : sig
   end
 end
 
+type proof = (Pickles_types.Nat.N0.n, Pickles_types.Nat.N0.n) Pickles.Proof.t
+
 type pickles_rule_js =
   < identifier : Js.js_string Js.t Js.prop
   ; main :
@@ -35,14 +37,14 @@ type pickles_rule_js =
   ; proofsToVerify :
       < isSelf : bool Js.t Js.prop ; tag : Js.Unsafe.any Js.t Js.prop > Js.t
       array
-      Js.prop >
+      Js.prop 
+  ; previousProofs : proof array Js.prop >
   Js.t
 
 module Cache : sig
   type js_storable
 end
 
-type proof = (Pickles_types.Nat.N0.n, Pickles_types.Nat.N0.n) Pickles.Proof.t
 
 module Proof0 : sig
   type t = (Pickles_types.Nat.N0.n, Pickles_types.Nat.N0.n) Pickles.Proof.t