diff --git a/test/proto_alpha/proto_alpha_helpers.ml b/test/proto_alpha/proto_alpha_helpers.ml
index 3c08bb9c3..3200188fc 100644
--- a/test/proto_alpha/proto_alpha_helpers.ml
+++ b/test/proto_alpha/proto_alpha_helpers.ml
@@ -422,6 +422,7 @@ module Mining = struct
   let mine
       ?(force = false)
       ?(operations = [])
+      ~fitness_gap
       contract
       block =
   Client_mining_blocks.info rpc_config block >>=? fun bi ->
@@ -438,8 +439,7 @@ module Mining = struct
    Register_client_embedded_proto_alpha.wrap_error) >>=? fun fitness ->
   let fitness =
     Fitness_repr.from_int64 @@
-    Int64.add fitness (Int64.of_int @@ List.length operations + 1) in
-  Level.pp_full Format.str_formatter bi.level ;
+    Int64.add fitness (Int64.of_int fitness_gap) in
   inject_block
     ~force
     ~priority
diff --git a/test/proto_alpha/proto_alpha_helpers.mli b/test/proto_alpha/proto_alpha_helpers.mli
index 689f5f77d..008d59756 100644
--- a/test/proto_alpha/proto_alpha_helpers.mli
+++ b/test/proto_alpha/proto_alpha_helpers.mli
@@ -122,6 +122,7 @@ module Mining : sig
   val mine :
     ?force:bool ->
     ?operations:Operation_hash.t list ->
+    fitness_gap:int ->
     Account.t ->
     Client_node_rpcs.Blocks.block ->
     Block_hash.t tzresult Lwt.t
diff --git a/test/proto_alpha/test_endorsement.ml b/test/proto_alpha/test_endorsement.ml
index 9c6db5770..86c61d5ec 100644
--- a/test/proto_alpha/test_endorsement.ml
+++ b/test/proto_alpha/test_endorsement.ml
@@ -16,25 +16,25 @@ module Assert = Helpers.Assert
 let test_double_endorsement contract block =
 
   (* Double endorsement for the same level *)
-  Helpers.Mining.mine contract block >>=? fun b1 ->
+  Helpers.Mining.mine ~fitness_gap:1 contract block >>=? fun b1 ->
 
   (* branch root *)
-  Helpers.Mining.mine contract (`Hash b1) >>=? fun b2 ->
+  Helpers.Mining.mine ~fitness_gap:1 contract (`Hash b1) >>=? fun b2 ->
   (* changing branch *)
-  Helpers.Mining.mine contract (`Hash b1) >>=? fun b2' ->
+  Helpers.Mining.mine ~fitness_gap:1 contract (`Hash b1) >>=? fun b2' ->
 
   (* branch root *)
   Helpers.Endorse.endorse ~force:true contract (`Hash b2) >>=? fun ops ->
-  Helpers.Mining.mine ~operations:[ ops ] contract (`Hash b2) >>=? fun _b3 ->
+  Helpers.Mining.mine ~fitness_gap:2 ~operations:[ ops ] contract (`Hash b2) >>=? fun _b3 ->
 
   Helpers.Endorse.endorse ~force:true contract (`Hash b2') >>=? fun ops ->
-  Helpers.Mining.mine ~operations:[ ops ] contract (`Hash b2') >>=? fun b3' ->
+  Helpers.Mining.mine ~fitness_gap:2 ~operations:[ ops ] contract (`Hash b2') >>=? fun b3' ->
 
   Helpers.Endorse.endorse ~force:true contract (`Hash b3') >>=? fun ops ->
-  Helpers.Mining.mine ~operations:[ ops ] contract (`Hash b3') >>=? fun b4' ->
+  Helpers.Mining.mine ~fitness_gap:2 ~operations:[ ops ] contract (`Hash b3') >>=? fun b4' ->
 
   (* TODO: Inject double endorsement op ! *)
-  Helpers.Mining.mine contract (`Hash b4')
+  Helpers.Mining.mine ~fitness_gap:1 contract (`Hash b4')
 
 (* FIXME: Mining.Invalid_signature is unclassified *)
 let test_invalid_signature block =
@@ -47,7 +47,7 @@ let test_invalid_signature block =
        DYfTKhq7rDQujdn5WWzwUMeV3agaZ6J2vPQT58jJAJPi" in
   let account =
     Helpers.Account.create ~keys:(secret_key, public_key) "WRONG SIGNATURE" in
-  Helpers.Mining.mine account block >>= fun res ->
+  Helpers.Mining.mine ~fitness_gap:1 account block >>= fun res ->
   Assert.generic_economic_error ~msg:__LOC__ res ;
   return ()
 
@@ -94,7 +94,7 @@ let test_endorsement_rewards
   get_endorser_except_b1 accounts >>=? fun (account0, slot0) ->
   Helpers.Account.balance account0 >>=? fun balance0 ->
   Helpers.Endorse.endorse ~slot:slot0 ~force:true account0 block >>=? fun ops ->
-  Helpers.Mining.mine ~operations:[ ops ] b1 block >>=? fun head0 ->
+  Helpers.Mining.mine ~fitness_gap:2 ~operations:[ ops ] b1 block >>=? fun head0 ->
   Assert.balance_equal ~msg:__LOC__ account0
     (Int64.sub (Tez.to_cents balance0) bond) >>=? fun () ->
 
@@ -104,7 +104,7 @@ let test_endorsement_rewards
   get_endorser_except_b1 accounts >>=? fun (account1, slot1) ->
   Helpers.Account.balance account1 >>=? fun balance1 ->
   Helpers.Endorse.endorse ~slot:slot1 ~force:true account1 block0 >>=? fun ops ->
-  Helpers.Mining.mine ~operations:[ ops ] b1 block0 >>=? fun head1 ->
+  Helpers.Mining.mine ~fitness_gap:2 ~operations:[ ops ] b1 block0 >>=? fun head1 ->
   Assert.balance_equal ~msg:__LOC__ account1
     (Int64.sub (Tez.to_cents balance1) bond) >>=? fun () ->
 
@@ -117,8 +117,8 @@ let test_endorsement_rewards
   Assert.balance_equal ~msg:__LOC__ account2
     (Int64.sub (Tez.to_cents balance2) bond) >>=? fun () ->
 
-  Helpers.Mining.mine b1 (`Hash head1) >>=? fun head2 ->
-  Helpers.Mining.mine b1 (`Hash head2) >>=? fun head3 ->
+  Helpers.Mining.mine ~fitness_gap:1 b1 (`Hash head1) >>=? fun head2 ->
+  Helpers.Mining.mine ~fitness_gap:1 b1 (`Hash head2) >>=? fun head3 ->
 
   (* Check rewards after one cycle for account0 *)
   Helpers.Mining.endorsement_reward b1 block0 >>=? fun rw0 ->
@@ -135,8 +135,8 @@ let test_endorsement_rewards
     ~msg:__LOC__ account2 (Tez.to_cents balance2) >>=? fun () ->
 
   (* #2 endorse and check reward only on the good chain  *)
-  Helpers.Mining.mine b1 (`Hash head3) >>=? fun head ->
-  Helpers.Mining.mine b1 (`Hash head3) >>=? fun fork ->
+  Helpers.Mining.mine ~fitness_gap:1 b1 (`Hash head3) >>=? fun head ->
+  Helpers.Mining.mine ~fitness_gap:1 b1 (`Hash head3) >>=? fun fork ->
 
   (* working on head *)
   Helpers.Endorse.endorsers_list (`Hash head) baccounts >>=? fun accounts ->
@@ -144,18 +144,18 @@ let test_endorsement_rewards
   Helpers.Account.balance account3 >>=? fun balance3 ->
   Helpers.Endorse.endorse
     ~slot:slot3 ~force:true account3 (`Hash head) >>=? fun ops ->
-  Helpers.Mining.mine ~operations:[ ops ] b1 (`Hash head) >>=? fun new_head ->
+  Helpers.Mining.mine ~fitness_gap:2 ~operations:[ ops ] b1 (`Hash head) >>=? fun new_head ->
 
   (* working on fork *)
   Helpers.Endorse.endorsers_list (`Hash fork) baccounts >>=? fun accounts ->
   get_endorser_except_b1 accounts >>=? fun (account4, slot4) ->
   Helpers.Account.balance account4 >>=? fun _balance4 ->
   Helpers.Endorse.endorse ~slot:slot4 ~force:true account4 (`Hash fork) >>=? fun ops ->
-  Helpers.Mining.mine ~operations:[ ops ] b1 (`Hash fork) >>=? fun _new_fork ->
+  Helpers.Mining.mine ~fitness_gap:2 ~operations:[ ops ] b1 (`Hash fork) >>=? fun _new_fork ->
   Helpers.Account.balance account4 >>=? fun balance4 ->
 
-  Helpers.Mining.mine b1 (`Hash new_head) >>=? fun head ->
-  Helpers.Mining.mine b1 (`Hash head) >>=? fun head ->
+  Helpers.Mining.mine ~fitness_gap:1 b1 (`Hash new_head) >>=? fun head ->
+  Helpers.Mining.mine ~fitness_gap:1 b1 (`Hash head) >>=? fun head ->
 
   (* Check rewards after one cycle *)
   Helpers.Mining.endorsement_reward b1 (`Hash new_head) >>=? fun reward ->
diff --git a/test/proto_alpha/test_origination.ml b/test/proto_alpha/test_origination.ml
index d6523f68f..265cd41e9 100644
--- a/test/proto_alpha/test_origination.ml
+++ b/test/proto_alpha/test_origination.ml
@@ -15,7 +15,7 @@ module Assert = Helpers.Assert
 
 let run blkid ({ b1 ; b2 ; _ } : Helpers.Account.bootstrap_accounts) =
 
-  Helpers.Mining.mine b1 blkid >>=? fun blkh ->
+  Helpers.Mining.mine ~fitness_gap:1 b1 blkid >>=? fun blkh ->
   let foo = Helpers.Account.create "foo" in
 
   (* Origination with amount = 0 tez *)
diff --git a/test/proto_alpha/test_transaction.ml b/test/proto_alpha/test_transaction.ml
index af3802f06..abf8a64ba 100644
--- a/test/proto_alpha/test_transaction.ml
+++ b/test/proto_alpha/test_transaction.ml
@@ -15,7 +15,7 @@ module Assert = Helpers.Assert
 
 let run blkid ({ b1 ; b2 ; b3 ; _ } : Helpers.Account.bootstrap_accounts) =
 
-  Helpers.Mining.mine b1 blkid >>=? fun blkh ->
+  Helpers.Mining.mine ~fitness_gap:1 b1 blkid >>=? fun blkh ->
   let foo = Helpers.Account.create "foo" in
   let bar = Helpers.Account.create "bar" in