diff --git a/src/proto_alpha/lib_protocol/test/main.ml b/src/proto_alpha/lib_protocol/test/main.ml
index 2085eba43..58dc30fb5 100644
--- a/src/proto_alpha/lib_protocol/test/main.ml
+++ b/src/proto_alpha/lib_protocol/test/main.ml
@@ -15,4 +15,5 @@ let () =
     "endorsement", Endorsement.tests ;
     "double endorsement", Double_endorsement.tests ;
     "double baking", Double_baking.tests ;
+    "seed", Seed.tests ;
   ]
diff --git a/src/proto_alpha/lib_protocol/test/seed.ml b/src/proto_alpha/lib_protocol/test/seed.ml
new file mode 100644
index 000000000..3617d7fb0
--- /dev/null
+++ b/src/proto_alpha/lib_protocol/test/seed.ml
@@ -0,0 +1,80 @@
+(**************************************************************************)
+(*                                                                        *)
+(*    Copyright (c) 2014 - 2018.                                          *)
+(*    Dynamic Ledger Solutions, Inc. <contact@tezos.com>                  *)
+(*                                                                        *)
+(*    All rights reserved. No warranty, explicit or implicit, provided.   *)
+(*                                                                        *)
+(**************************************************************************)
+
+open Proto_alpha
+open Alpha_context
+
+(** Tests that baking [blocks_per_cycle] blocks without a
+    [seed_nonce_hash] commitment fails with [Invalid_commitment] *)
+let no_commitment () =
+  Context.init 5 >>=? fun (b,_) ->
+  Context.get_constants (B b) >>=? fun { parametric = csts } ->
+  let blocks_per_cycle = Int32.to_int csts.blocks_per_cycle in
+
+  (* Bake normally until before the commitment *)
+  Block.bake_n (blocks_per_cycle-2) b >>=? fun b ->
+
+  (* Forge a block with empty commitment and apply it *)
+  Block.Forge.forge_header b >>=? fun header ->
+  let header = Block.Forge.set_seed_nonce_hash None header in
+  Block.apply header b >>= fun e ->
+
+  let invalid_commitment = function
+    | Proto_alpha.Apply.Invalid_commitment _ -> true
+    | _ -> false in
+  Assert.proto_error ~loc:__LOC__ e invalid_commitment
+
+
+(** checks that if a baker of cycle 0 doesn't reveal its seed_nonce at cycle 1,
+    it will loose its rewards and fees at the end of cycle 1 *)
+let no_revelation () =
+  let open Assert in
+
+  Context.init 5 >>=? fun (b,_) ->
+  Context.get_constants (B b) >>=? fun csts ->
+  let bond = csts.parametric.block_security_deposit in
+  let reward = csts.parametric.block_reward in
+  let blocks_per_commitment = Int32.to_int csts.parametric.blocks_per_commitment in
+
+  (* bake until commitment *)
+  Block.bake_n (blocks_per_commitment-2) b >>=? fun b ->
+
+  (* bake with commitment *)
+  Block.get_next_baker b >>=? fun (pkh,_,_) ->
+  let id = Contract.implicit_contract pkh in
+  Context.Contract.balance (B b) id >>=? fun bal_main ->
+  Context.Contract.balance ~kind:Deposit (B b) id >>=? fun bal_deposit ->
+  Context.Contract.balance ~kind:Rewards (B b) id >>=? fun bal_rewards ->
+  Block.bake ~policy:(Block.By_account pkh) b >>=? fun b ->
+  balance_was_debited ~loc:__LOC__
+    (B b) id bal_main bond >>=? fun () ->
+  balance_was_credited ~loc:__LOC__
+    (B b) id ~kind:Deposit bal_deposit bond >>=? fun () ->
+  balance_was_credited ~loc:__LOC__
+    (B b) id ~kind:Rewards bal_rewards reward >>=? fun () ->
+
+  Context.Contract.balance (B b) id >>=? fun bal_main ->
+  Context.Contract.balance ~kind:Rewards (B b) id >>=? fun bal_rewards ->
+  (* finish the cycle excluding the committing baker *)
+  let policy = Block.Excluding [pkh] in
+  Block.bake_until_cycle_end ~policy b >>=? fun b ->
+  (* one cycle w/o revelation (or baking) from committing baker *)
+  Block.bake_until_cycle_end ~policy b >>=? fun b ->
+
+  (* the reward is lost *)
+  balance_is ~loc:__LOC__ (B b) id ~kind:Main bal_main >>=? fun () ->
+  balance_was_debited ~loc:__LOC__
+    (B b) id ~kind:Rewards bal_rewards reward >>=? fun _ ->
+  return ()
+
+
+let tests = [
+  Test.tztest "no commitment" `Quick no_commitment;
+  Test.tztest "no revelation" `Quick no_revelation;
+]