diff --git a/src/proto_alpha/lib_protocol/michelson_v1_gas_costs.ml b/src/proto_alpha/lib_protocol/michelson_v1_gas_costs.ml
index fde9a3ab4fa63b0e1a39722de411c583d577de4f..eeeaa93335bb453f92cedac51544ca5af03ce808 100644
--- a/src/proto_alpha/lib_protocol/michelson_v1_gas_costs.ml
+++ b/src/proto_alpha/lib_protocol/michelson_v1_gas_costs.ml
@@ -55,13 +55,15 @@ let cost_N_IEdiv_teznat = S.safe_int 70
    Such code can't be generated by the current Snoop. *)
 
 (* model N_ISapling_verify_update *)
+(* Inferred cost (without cost_N_IBlake2b) is:
+   fun size1 -> fun size2 -> ((432200.469784 + (5738377.05148 * size1)) + (4634026.28586 * size2)) *)
 let cost_N_ISapling_verify_update size1 size2 bound_data =
   let open S.Syntax in
   let v1 = S.safe_int size1 in
   let v2 = S.safe_int size2 in
-  cost_N_IBlake2b bound_data + S.safe_int 310_000
-  + (S.safe_int 5_575_000 * v1)
-  + (S.safe_int 5_075_000 * v2)
+  cost_N_IBlake2b bound_data + S.safe_int 432_500
+  + (S.safe_int 5_740_000 * v1)
+  + (S.safe_int 4_635_000 * v2)
 
 (* N_IApply
    The current generated model receives int as a flag,