diff --git a/src/proto_alpha/lib_protocol/test/helpers/block.ml b/src/proto_alpha/lib_protocol/test/helpers/block.ml
index 31d95d422..0ec951c81 100644
--- a/src/proto_alpha/lib_protocol/test/helpers/block.ml
+++ b/src/proto_alpha/lib_protocol/test/helpers/block.ml
@@ -151,7 +151,8 @@ module Forge = struct
   let contents
       ?(proof_of_work_nonce = default_proof_of_work_nonce)
       ?(priority = 0) ?seed_nonce_hash () =
-    { Block_header.priority ;
+    {
+      Block_header.priority ;
       proof_of_work_nonce ;
       seed_nonce_hash ;
     }
@@ -349,12 +350,12 @@ let bake ?policy ?operation ?operations pred =
   Forge.sign_header header >>=? fun header ->
   apply header ?operations pred
 
+(********** Cycles ****************)
+
 (* This function is duplicated from Context to avoid a cyclic dependency *)
 let get_constants b =
   Alpha_services.Constants.all rpc_ctxt b
 
-(********** Cycles ****************)
-
 let bake_n ?policy n b =
   Error_monad.fold_left_s
     (fun b _ -> bake ?policy b) b (1 -- n)
diff --git a/src/proto_alpha/lib_protocol/test/helpers/test_tez.ml b/src/proto_alpha/lib_protocol/test/helpers/test_tez.ml
index 35e7a45f6..5bad1992f 100644
--- a/src/proto_alpha/lib_protocol/test/helpers/test_tez.ml
+++ b/src/proto_alpha/lib_protocol/test/helpers/test_tez.ml
@@ -30,4 +30,16 @@ module Tez = struct
     match Tez.of_mutez (Int64.mul (Int64.of_int x) 1_000_000L) with
     | None -> invalid_arg "tez_of_int"
     | Some x -> x
+
+  let of_mutez_exn x =
+    match Tez.of_mutez x with
+    | None -> invalid_arg "tez_of_mutez"
+    | Some x -> x
+
+
+  let max_tez =
+    match Tez.of_mutez Int64.max_int with
+    | None -> assert false
+    | Some p -> p
+
 end
diff --git a/src/proto_alpha/lib_protocol/test/transfer.ml b/src/proto_alpha/lib_protocol/test/transfer.ml
index 872439787..86b981750 100644
--- a/src/proto_alpha/lib_protocol/test/transfer.ml
+++ b/src/proto_alpha/lib_protocol/test/transfer.ml
@@ -49,11 +49,6 @@ let n_transactions n b ?fee source dest amount =
 
 let ten_tez = Tez.of_int 10
 
-let max_tez =
-  match Tez.of_mutez Int64.max_int with
-  | None -> assert false
-  | Some p -> p
-
 (*********************************************************************)
 (* Tests                                                             *)
 (*********************************************************************)
@@ -301,7 +296,7 @@ let balance_too_low fee () =
   Incremental.begin_construction b >>=? fun i ->
   Context.Contract.balance (I i) contract_1 >>=? fun balance1 ->
   Context.Contract.balance (I i) contract_2 >>=? fun balance2 ->
-  Op.transaction ~fee (I i) contract_1 contract_2 max_tez >>=? fun op ->
+  Op.transaction ~fee (I i) contract_1 contract_2 Tez.max_tez >>=? fun op ->
   let expect_failure = function
     | Alpha_environment.Ecoproto_error (Contract_storage.Balance_too_low _) :: _ ->
         return ()