diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index b0490cba5..1ff1d58b3 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -1137,14 +1137,16 @@ When `is_genesis_trigger(deposits, time) is True` for the first time let:
 
 ```python
 def is_genesis_trigger(deposits: List[Deposit, 2**DEPOSIT_CONTRACT_TREE_DEPTH], time: uint64) -> bool:
+    SECONDS_PER_DAY = 86400
     # Do not deploy too early
     if time - time % SECONDS_PER_DAY + 2 * SECONDS_PER_DAY < MIN_GENESIS_TIME:
         return False
 
     # Initialize deposit root
     state = BeaconState()
-    state.eth1_data.deposit_root = hash_tree_root(map(deposits, lambda deposit: deposit.data))
-
+    state.eth1_data.deposit_root = hash_tree_root(
+        Vector[DepositData, len(deposits)](list(map(lambda deposit: deposit.data, deposits)))
+    )
     # Process deposits
     for deposit in deposits:
         process_deposit(state, deposit)
diff --git a/test_libs/pyspec/eth2spec/test/genesis/test_genesis_trigger.py b/test_libs/pyspec/eth2spec/test/genesis/test_genesis_trigger.py
index 873638dc9..9425a1750 100644
--- a/test_libs/pyspec/eth2spec/test/genesis/test_genesis_trigger.py
+++ b/test_libs/pyspec/eth2spec/test/genesis/test_genesis_trigger.py
@@ -26,7 +26,8 @@ def test_is_genesis_trigger_false(spec):
 def test_is_genesis_trigger_true(spec):
     deposit_count = spec.GENESIS_ACTIVE_VALIDATOR_COUNT
     genesis_deposits, deposit_root = prepare_genesis_deposits(spec, deposit_count, spec.MAX_EFFECTIVE_BALANCE)
-    genesis_time = 1546300800
+    SECONDS_PER_DAY = 86400
+    genesis_time = 1578009600 - 2 * SECONDS_PER_DAY
 
     yield "deposits", genesis_deposits
     yield "time", genesis_time
diff --git a/test_libs/pyspec/eth2spec/test/helpers/deposits.py b/test_libs/pyspec/eth2spec/test/helpers/deposits.py
index eea019e8b..bda4f1699 100644
--- a/test_libs/pyspec/eth2spec/test/helpers/deposits.py
+++ b/test_libs/pyspec/eth2spec/test/helpers/deposits.py
@@ -82,7 +82,7 @@ def prepare_genesis_deposits(spec, genesis_validator_count, amount, signed=False
     tree = calc_merkle_tree_from_leaves(tuple(deposit_data_leaves))
     root = get_merkle_root((tuple(deposit_data_leaves)))
 
-    genesis_deposits = (
+    genesis_deposits = list(
         spec.Deposit(proof=list(get_merkle_proof(tree, item_index=index)), data=deposit_data)
         for index, deposit_data in enumerate(genesis_deposit_data_list)
     )