diff --git a/specs/altair/sync-protocol.md b/specs/altair/sync-protocol.md
index fe7882ff9..f6809eab5 100644
--- a/specs/altair/sync-protocol.md
+++ b/specs/altair/sync-protocol.md
@@ -16,6 +16,7 @@
   - [`LightClientUpdate`](#lightclientupdate)
   - [`LightClientStore`](#lightclientstore)
 - [Helper functions](#helper-functions)
+  - [`is_finality_update`](#is_finality_update)
   - [`get_subtree_index`](#get_subtree_index)
   - [`get_active_header`](#get_active_header)
   - [`get_safety_threshold`](#get_safety_threshold)
@@ -95,6 +96,13 @@ class LightClientStore(object):
 
 ## Helper functions
 
+### `is_finality_update`
+
+```python
+def is_finality_update(update: LightClientUpdate) -> bool:
+    return update.finalized_header != BeaconBlockHeader()
+```
+
 ### `get_subtree_index`
 
 ```python
@@ -109,7 +117,7 @@ def get_active_header(update: LightClientUpdate) -> BeaconBlockHeader:
     # The "active header" is the header that the update is trying to convince us
     # to accept. If a finalized header is present, it's the finalized header,
     # otherwise it's the attested header
-    if update.finalized_header != BeaconBlockHeader():
+    if is_finality_update(update):
         return update.finalized_header
     else:
         return update.attested_header
@@ -157,13 +165,13 @@ def validate_light_client_update(store: LightClientStore,
     assert current_slot >= active_header.slot > store.finalized_header.slot
 
     # Verify update does not skip a sync committee period
-    finalized_period = compute_epoch_at_slot(store.finalized_header.slot) // EPOCHS_PER_SYNC_COMMITTEE_PERIOD
-    update_period = compute_epoch_at_slot(active_header.slot) // EPOCHS_PER_SYNC_COMMITTEE_PERIOD
+    finalized_period = compute_sync_committee_period(compute_epoch_at_slot(store.finalized_header.slot))
+    update_period = compute_sync_committee_period(compute_epoch_at_slot(active_header.slot))
     assert update_period in (finalized_period, finalized_period + 1)
 
     # Verify that the `finalized_header`, if present, actually is the finalized header saved in the
     # state of the `attested header`
-    if update.finalized_header == BeaconBlockHeader():
+    if not is_finality_update(update):
         assert update.finality_branch == [Bytes32() for _ in range(floorlog2(FINALIZED_ROOT_INDEX))]
     else:
         assert is_valid_merkle_branch(
@@ -208,12 +216,14 @@ def validate_light_client_update(store: LightClientStore,
 ```python
 def apply_light_client_update(store: LightClientStore, update: LightClientUpdate) -> None:
     active_header = get_active_header(update)
-    finalized_period = compute_epoch_at_slot(store.finalized_header.slot) // EPOCHS_PER_SYNC_COMMITTEE_PERIOD
-    update_period = compute_epoch_at_slot(active_header.slot) // EPOCHS_PER_SYNC_COMMITTEE_PERIOD
+    finalized_period = compute_sync_committee_period(compute_epoch_at_slot(store.finalized_header.slot))
+    update_period = compute_sync_committee_period(compute_epoch_at_slot(active_header.slot))
     if update_period == finalized_period + 1:
         store.current_sync_committee = store.next_sync_committee
         store.next_sync_committee = update.next_sync_committee
     store.finalized_header = active_header
+    if store.finalized_header.slot > store.optimistic_header.slot:
+        store.optimistic_header = store.finalized_header
 ```
 
 #### `process_light_client_update`
@@ -250,7 +260,7 @@ def process_light_client_update(store: LightClientStore,
     # Update finalized header
     if (
         sum(sync_committee_bits) * 3 >= len(sync_committee_bits) * 2
-        and update.finalized_header != BeaconBlockHeader()
+        and is_finality_update(update)
     ):
         # Normal update through 2/3 threshold
         apply_light_client_update(store, update)
diff --git a/specs/bellatrix/beacon-chain.md b/specs/bellatrix/beacon-chain.md
index 63bad7f08..b37a8ab71 100644
--- a/specs/bellatrix/beacon-chain.md
+++ b/specs/bellatrix/beacon-chain.md
@@ -171,7 +171,7 @@ class ExecutionPayload(Container):
     state_root: Bytes32
     receipts_root: Bytes32
     logs_bloom: ByteVector[BYTES_PER_LOGS_BLOOM]
-    random: Bytes32  # 'difficulty' in the yellow paper
+    prev_randao: Bytes32  # 'difficulty' in the yellow paper
     block_number: uint64  # 'number' in the yellow paper
     gas_limit: uint64
     gas_used: uint64
@@ -193,7 +193,7 @@ class ExecutionPayloadHeader(Container):
     state_root: Bytes32
     receipts_root: Bytes32
     logs_bloom: ByteVector[BYTES_PER_LOGS_BLOOM]
-    random: Bytes32
+    prev_randao: Bytes32
     block_number: uint64
     gas_limit: uint64
     gas_used: uint64
@@ -348,8 +348,8 @@ def process_execution_payload(state: BeaconState, payload: ExecutionPayload, exe
     # Verify consistency of the parent hash with respect to the previous execution payload header
     if is_merge_transition_complete(state):
         assert payload.parent_hash == state.latest_execution_payload_header.block_hash
-    # Verify random
-    assert payload.random == get_randao_mix(state, get_current_epoch(state))
+    # Verify prev_randao
+    assert payload.prev_randao == get_randao_mix(state, get_current_epoch(state))
     # Verify timestamp
     assert payload.timestamp == compute_timestamp_at_slot(state, state.slot)
     # Verify the execution payload is valid
@@ -361,7 +361,7 @@ def process_execution_payload(state: BeaconState, payload: ExecutionPayload, exe
         state_root=payload.state_root,
         receipts_root=payload.receipts_root,
         logs_bloom=payload.logs_bloom,
-        random=payload.random,
+        prev_randao=payload.prev_randao,
         block_number=payload.block_number,
         gas_limit=payload.gas_limit,
         gas_used=payload.gas_used,
diff --git a/specs/bellatrix/fork-choice.md b/specs/bellatrix/fork-choice.md
index 91fda88bc..0f5a7b646 100644
--- a/specs/bellatrix/fork-choice.md
+++ b/specs/bellatrix/fork-choice.md
@@ -80,7 +80,7 @@ Used to signal to initiate the payload build process via `notify_forkchoice_upda
 @dataclass
 class PayloadAttributes(object):
     timestamp: uint64
-    random: Bytes32
+    prev_randao: Bytes32
     suggested_fee_recipient: ExecutionAddress
 ```
 
diff --git a/specs/bellatrix/validator.md b/specs/bellatrix/validator.md
index 7e0369a39..47de49ba6 100644
--- a/specs/bellatrix/validator.md
+++ b/specs/bellatrix/validator.md
@@ -143,7 +143,7 @@ def prepare_execution_payload(state: BeaconState,
     # Set the forkchoice head and initiate the payload build process
     payload_attributes = PayloadAttributes(
         timestamp=compute_timestamp_at_slot(state, state.slot),
-        random=get_randao_mix(state, get_current_epoch(state)),
+        prev_randao=get_randao_mix(state, get_current_epoch(state)),
         suggested_fee_recipient=suggested_fee_recipient,
     )
     return execution_engine.notify_forkchoice_updated(parent_hash, finalized_block_hash, payload_attributes)
diff --git a/specs/das/p2p-interface.md b/specs/das/p2p-interface.md
index b4a0a9d2c..b1d96c718 100644
--- a/specs/das/p2p-interface.md
+++ b/specs/das/p2p-interface.md
@@ -196,11 +196,6 @@ This builds on top of the protocol identification and encoding spec which was in
 
 Note that DAS networking uses a different protocol prefix: `/eth2/das/req`
 
-The result codes are extended with:
--  3: **ResourceUnavailable** -- when the request was valid but cannot be served at this point in time.
-
-TODO: unify with phase0? Lighthoue already defined this in their response codes enum.
-
 ### Messages
 
 #### DASQuery
diff --git a/specs/phase0/p2p-interface.md b/specs/phase0/p2p-interface.md
index f5c138f99..0a0eb1192 100644
--- a/specs/phase0/p2p-interface.md
+++ b/specs/phase0/p2p-interface.md
@@ -337,6 +337,8 @@ The following validations MUST pass before forwarding the `signed_aggregate_and_
   (a client MAY queue future aggregates for processing at the appropriate slot).
 - _[REJECT]_ The aggregate attestation's epoch matches its target -- i.e. `aggregate.data.target.epoch ==
   compute_epoch_at_slot(aggregate.data.slot)`
+- _[IGNORE]_ The valid aggregate attestation defined by `hash_tree_root(aggregate)` has _not_ already been seen
+  (via aggregate gossip, within a verified block, or through the creation of an equivalent aggregate locally).
 - _[IGNORE]_ The `aggregate` is the first valid aggregate received for the aggregator
   with index `aggregate_and_proof.aggregator_index` for the epoch `aggregate.data.target.epoch`.
 - _[REJECT]_ The attestation has participants --
@@ -424,7 +426,7 @@ The following validations MUST pass before forwarding the `attestation` on the s
 - _[REJECT]_ The block being voted for (`attestation.data.beacon_block_root`) passes validation.
 - _[REJECT]_ The attestation's target block is an ancestor of the block named in the LMD vote -- i.e.
   `get_ancestor(store, attestation.data.beacon_block_root, compute_start_slot_at_epoch(attestation.data.target.epoch)) == attestation.data.target.root`
-- _[REJECT]_ The current `finalized_checkpoint` is an ancestor of the `block` defined by `attestation.data.beacon_block_root` -- i.e.
+- _[IGNORE]_ The current `finalized_checkpoint` is an ancestor of the `block` defined by `attestation.data.beacon_block_root` -- i.e.
   `get_ancestor(store, attestation.data.beacon_block_root, compute_start_slot_at_epoch(store.finalized_checkpoint.epoch))
   == store.finalized_checkpoint.root`
 
@@ -569,11 +571,11 @@ The response code can have one of the following values, encoded as a single unsi
   The response payload adheres to the `ErrorMessage` schema (described below).
 -  3: **ResourceUnavailable** -- the responder does not have requested resource.
   The response payload adheres to the `ErrorMessage` schema (described below).
-  *Note*: This response code is only valid as a response to `BlocksByRange`.
+  *Note*: This response code is only valid as a response where specified.
 
 Clients MAY use response codes above `128` to indicate alternative, erroneous request-specific responses.
 
-The range `[3, 127]` is RESERVED for future usages, and should be treated as error if not recognized expressly.
+The range `[4, 127]` is RESERVED for future usages, and should be treated as error if not recognized expressly.
 
 The `ErrorMessage` schema is:
 
diff --git a/sync/optimistic.md b/sync/optimistic.md
index b44384d34..8e6acc442 100644
--- a/sync/optimistic.md
+++ b/sync/optimistic.md
@@ -82,9 +82,9 @@ def is_execution_block(block: BeaconBlock) -> bool:
 ```python
 def is_optimistic_candidate_block(opt_store: OptimisticStore, current_slot: Slot, block: BeaconBlock) -> bool:
     justified_root = opt_store.block_states[opt_store.head_block_root].current_justified_checkpoint.root
-    justifed_is_execution_block = is_execution_block(opt_store.blocks[justified_root])
+    justified_is_execution_block = is_execution_block(opt_store.blocks[justified_root])
     block_is_deep = block.slot + SAFE_SLOTS_TO_IMPORT_OPTIMISTICALLY <= current_slot
-    return justifed_is_execution_block or block_is_deep
+    return justified_is_execution_block or block_is_deep
 ```
 
 Let only a node which returns `is_optimistic(opt_store, head) is True` be an *optimistic
diff --git a/tests/core/pyspec/eth2spec/VERSION.txt b/tests/core/pyspec/eth2spec/VERSION.txt
index a5e428299..9695327b3 100644
--- a/tests/core/pyspec/eth2spec/VERSION.txt
+++ b/tests/core/pyspec/eth2spec/VERSION.txt
@@ -1 +1 @@
-1.1.9
\ No newline at end of file
+1.1.10
\ No newline at end of file
diff --git a/tests/core/pyspec/eth2spec/test/altair/epoch_processing/test_process_sync_committee_updates.py b/tests/core/pyspec/eth2spec/test/altair/epoch_processing/test_process_sync_committee_updates.py
index 1667a12b2..4b0cb70d5 100644
--- a/tests/core/pyspec/eth2spec/test/altair/epoch_processing/test_process_sync_committee_updates.py
+++ b/tests/core/pyspec/eth2spec/test/altair/epoch_processing/test_process_sync_committee_updates.py
@@ -24,7 +24,7 @@ def run_sync_committees_progress_test(spec, state):
     first_sync_committee = state.current_sync_committee.copy()
     second_sync_committee = state.next_sync_committee.copy()
 
-    current_period = spec.get_current_epoch(state) // spec.EPOCHS_PER_SYNC_COMMITTEE_PERIOD
+    current_period = spec.compute_sync_committee_period(spec.get_current_epoch(state))
     next_period = current_period + 1
     next_period_start_epoch = next_period * spec.EPOCHS_PER_SYNC_COMMITTEE_PERIOD
     next_period_start_slot = next_period_start_epoch * spec.SLOTS_PER_EPOCH
diff --git a/tests/core/pyspec/eth2spec/test/altair/unittests/test_sync_protocol.py b/tests/core/pyspec/eth2spec/test/altair/unittests/test_sync_protocol.py
index 120004654..04553b3f8 100644
--- a/tests/core/pyspec/eth2spec/test/altair/unittests/test_sync_protocol.py
+++ b/tests/core/pyspec/eth2spec/test/altair/unittests/test_sync_protocol.py
@@ -5,38 +5,29 @@ from eth2spec.test.context import (
     with_presets,
     with_altair_and_later,
 )
-from eth2spec.test.helpers.attestations import next_epoch_with_attestations
+from eth2spec.test.helpers.attestations import (
+    next_epoch_with_attestations,
+)
 from eth2spec.test.helpers.block import (
     build_empty_block,
     build_empty_block_for_next_slot,
 )
 from eth2spec.test.helpers.constants import MINIMAL
+from eth2spec.test.helpers.light_client import (
+    get_sync_aggregate,
+    initialize_light_client_store,
+)
 from eth2spec.test.helpers.state import (
     next_slots,
     state_transition_and_sign_block,
 )
-from eth2spec.test.helpers.sync_committee import (
-    compute_aggregate_sync_committee_signature,
-)
 from eth2spec.test.helpers.merkle import build_proof
 
 
-def _initialize_light_client_store(spec, state):
-    return spec.LightClientStore(
-        finalized_header=spec.BeaconBlockHeader(),
-        current_sync_committee=state.current_sync_committee,
-        next_sync_committee=state.next_sync_committee,
-        best_valid_update=None,
-        optimistic_header=spec.BeaconBlockHeader(),
-        previous_max_active_participants=0,
-        current_max_active_participants=0,
-    )
-
-
 @with_altair_and_later
 @spec_state_test
 def test_process_light_client_update_not_timeout(spec, state):
-    store = _initialize_light_client_store(spec, state)
+    store = initialize_light_client_store(spec, state)
 
     # Block at slot 1 doesn't increase sync committee period, so it won't force update store.finalized_header
     block = build_empty_block_for_next_slot(spec, state)
@@ -49,19 +40,7 @@ def test_process_light_client_update_not_timeout(spec, state):
         body_root=signed_block.message.body.hash_tree_root(),
     )
     # Sync committee signing the header
-    all_pubkeys = [v.pubkey for v in state.validators]
-    committee = [all_pubkeys.index(pubkey) for pubkey in state.current_sync_committee.pubkeys]
-    sync_committee_bits = [True] * len(committee)
-    sync_committee_signature = compute_aggregate_sync_committee_signature(
-        spec,
-        state,
-        block_header.slot,
-        committee,
-    )
-    sync_aggregate = spec.SyncAggregate(
-        sync_committee_bits=sync_committee_bits,
-        sync_committee_signature=sync_committee_signature,
-    )
+    sync_aggregate = get_sync_aggregate(spec, state, block_header, block_root=None)
     next_sync_committee_branch = [spec.Bytes32() for _ in range(spec.floorlog2(spec.NEXT_SYNC_COMMITTEE_INDEX))]
 
     # Ensure that finality checkpoint is genesis
@@ -94,12 +73,12 @@ def test_process_light_client_update_not_timeout(spec, state):
 @spec_state_test
 @with_presets([MINIMAL], reason="too slow")
 def test_process_light_client_update_timeout(spec, state):
-    store = _initialize_light_client_store(spec, state)
+    store = initialize_light_client_store(spec, state)
 
     # Forward to next sync committee period
     next_slots(spec, state, spec.UPDATE_TIMEOUT)
-    snapshot_period = spec.compute_epoch_at_slot(store.optimistic_header.slot) // spec.EPOCHS_PER_SYNC_COMMITTEE_PERIOD
-    update_period = spec.compute_epoch_at_slot(state.slot) // spec.EPOCHS_PER_SYNC_COMMITTEE_PERIOD
+    snapshot_period = spec.compute_sync_committee_period(spec.compute_epoch_at_slot(store.optimistic_header.slot))
+    update_period = spec.compute_sync_committee_period(spec.compute_epoch_at_slot(state.slot))
     assert snapshot_period + 1 == update_period
 
     block = build_empty_block_for_next_slot(spec, state)
@@ -113,20 +92,8 @@ def test_process_light_client_update_timeout(spec, state):
     )
 
     # Sync committee signing the finalized_block_header
-    all_pubkeys = [v.pubkey for v in state.validators]
-    committee = [all_pubkeys.index(pubkey) for pubkey in state.current_sync_committee.pubkeys]
-    sync_committee_bits = [True] * len(committee)
-    sync_committee_signature = compute_aggregate_sync_committee_signature(
-        spec,
-        state,
-        block_header.slot,
-        committee,
-        block_root=spec.Root(block_header.hash_tree_root()),
-    )
-    sync_aggregate = spec.SyncAggregate(
-        sync_committee_bits=sync_committee_bits,
-        sync_committee_signature=sync_committee_signature,
-    )
+    sync_aggregate = get_sync_aggregate(
+        spec, state, block_header, block_root=spec.Root(block_header.hash_tree_root()))
 
     # Sync committee is updated
     next_sync_committee_branch = build_proof(state.get_backing(), spec.NEXT_SYNC_COMMITTEE_INDEX)
@@ -158,7 +125,7 @@ def test_process_light_client_update_timeout(spec, state):
 @spec_state_test
 @with_presets([MINIMAL], reason="too slow")
 def test_process_light_client_update_finality_updated(spec, state):
-    store = _initialize_light_client_store(spec, state)
+    store = initialize_light_client_store(spec, state)
 
     # Change finality
     blocks = []
@@ -169,8 +136,8 @@ def test_process_light_client_update_finality_updated(spec, state):
     # Ensure that finality checkpoint has changed
     assert state.finalized_checkpoint.epoch == 3
     # Ensure that it's same period
-    snapshot_period = spec.compute_epoch_at_slot(store.optimistic_header.slot) // spec.EPOCHS_PER_SYNC_COMMITTEE_PERIOD
-    update_period = spec.compute_epoch_at_slot(state.slot) // spec.EPOCHS_PER_SYNC_COMMITTEE_PERIOD
+    snapshot_period = spec.compute_sync_committee_period(spec.compute_epoch_at_slot(store.optimistic_header.slot))
+    update_period = spec.compute_sync_committee_period(spec.compute_epoch_at_slot(state.slot))
     assert snapshot_period == update_period
 
     # Updated sync_committee and finality
@@ -191,20 +158,8 @@ def test_process_light_client_update_finality_updated(spec, state):
     )
 
     # Sync committee signing the finalized_block_header
-    all_pubkeys = [v.pubkey for v in state.validators]
-    committee = [all_pubkeys.index(pubkey) for pubkey in state.current_sync_committee.pubkeys]
-    sync_committee_bits = [True] * len(committee)
-    sync_committee_signature = compute_aggregate_sync_committee_signature(
-        spec,
-        state,
-        block_header.slot,
-        committee,
-        block_root=spec.Root(block_header.hash_tree_root()),
-    )
-    sync_aggregate = spec.SyncAggregate(
-        sync_committee_bits=sync_committee_bits,
-        sync_committee_signature=sync_committee_signature,
-    )
+    sync_aggregate = get_sync_aggregate(
+        spec, state, block_header, block_root=spec.Root(block_header.hash_tree_root()))
 
     update = spec.LightClientUpdate(
         attested_header=block_header,
diff --git a/tests/core/pyspec/eth2spec/test/bellatrix/block_processing/test_process_execution_payload.py b/tests/core/pyspec/eth2spec/test/bellatrix/block_processing/test_process_execution_payload.py
index a24e3e199..cd7a74259 100644
--- a/tests/core/pyspec/eth2spec/test/bellatrix/block_processing/test_process_execution_payload.py
+++ b/tests/core/pyspec/eth2spec/test/bellatrix/block_processing/test_process_execution_payload.py
@@ -153,7 +153,7 @@ def test_bad_random_first_payload(spec, state):
 
     # execution payload
     execution_payload = build_empty_execution_payload(spec, state)
-    execution_payload.random = b'\x42' * 32
+    execution_payload.prev_randao = b'\x42' * 32
 
     yield from run_execution_payload_processing(spec, state, execution_payload, valid=False)
 
@@ -167,7 +167,7 @@ def test_bad_random_regular_payload(spec, state):
 
     # execution payload
     execution_payload = build_empty_execution_payload(spec, state)
-    execution_payload.random = b'\x04' * 32
+    execution_payload.prev_randao = b'\x04' * 32
 
     yield from run_execution_payload_processing(spec, state, execution_payload, valid=False)
 
@@ -182,7 +182,7 @@ def test_bad_everything_regular_payload(spec, state):
     # execution payload
     execution_payload = build_empty_execution_payload(spec, state)
     execution_payload.parent_hash = spec.Hash32()
-    execution_payload.random = spec.Bytes32()
+    execution_payload.prev_randao = spec.Bytes32()
     execution_payload.timestamp = 0
 
     yield from run_execution_payload_processing(spec, state, execution_payload, valid=False)
diff --git a/tests/core/pyspec/eth2spec/test/bellatrix/unittests/validator/test_validator.py b/tests/core/pyspec/eth2spec/test/bellatrix/unittests/validator/test_validator.py
index 5e767d2cd..05a941dfe 100644
--- a/tests/core/pyspec/eth2spec/test/bellatrix/unittests/validator/test_validator.py
+++ b/tests/core/pyspec/eth2spec/test/bellatrix/unittests/validator/test_validator.py
@@ -103,7 +103,7 @@ def test_prepare_execution_payload(spec, state):
 
         # 1. Handle `is_merge_complete`
         if is_merge_complete:
-            state.latest_execution_payload_header = spec.ExecutionPayloadHeader(random=b'\x12' * 32)
+            state.latest_execution_payload_header = spec.ExecutionPayloadHeader(prev_randao=b'\x12' * 32)
         else:
             state.latest_execution_payload_header = spec.ExecutionPayloadHeader()
 
diff --git a/tests/core/pyspec/eth2spec/test/helpers/execution_payload.py b/tests/core/pyspec/eth2spec/test/helpers/execution_payload.py
index 49cec884a..14602a2cd 100644
--- a/tests/core/pyspec/eth2spec/test/helpers/execution_payload.py
+++ b/tests/core/pyspec/eth2spec/test/helpers/execution_payload.py
@@ -16,7 +16,7 @@ def build_empty_execution_payload(spec, state, randao_mix=None):
         receipts_root=b"no receipts here" + b"\x00" * 16,  # TODO: root of empty MPT may be better.
         logs_bloom=spec.ByteVector[spec.BYTES_PER_LOGS_BLOOM](),  # TODO: zeroed logs bloom for empty logs ok?
         block_number=latest.block_number + 1,
-        random=randao_mix,
+        prev_randao=randao_mix,
         gas_limit=latest.gas_limit,  # retain same limit
         gas_used=0,  # empty block, 0 gas
         timestamp=timestamp,
@@ -38,7 +38,7 @@ def get_execution_payload_header(spec, execution_payload):
         state_root=execution_payload.state_root,
         receipts_root=execution_payload.receipts_root,
         logs_bloom=execution_payload.logs_bloom,
-        random=execution_payload.random,
+        prev_randao=execution_payload.prev_randao,
         block_number=execution_payload.block_number,
         gas_limit=execution_payload.gas_limit,
         gas_used=execution_payload.gas_used,
diff --git a/tests/core/pyspec/eth2spec/test/helpers/genesis.py b/tests/core/pyspec/eth2spec/test/helpers/genesis.py
index 0539a5d74..d0e470893 100644
--- a/tests/core/pyspec/eth2spec/test/helpers/genesis.py
+++ b/tests/core/pyspec/eth2spec/test/helpers/genesis.py
@@ -30,7 +30,7 @@ def get_sample_genesis_execution_payload_header(spec,
         state_root=b'\x20' * 32,
         receipts_root=b'\x20' * 32,
         logs_bloom=b'\x35' * spec.BYTES_PER_LOGS_BLOOM,
-        random=eth1_block_hash,
+        prev_randao=eth1_block_hash,
         block_number=0,
         gas_limit=30000000,
         base_fee_per_gas=1000000000,
diff --git a/tests/core/pyspec/eth2spec/test/helpers/light_client.py b/tests/core/pyspec/eth2spec/test/helpers/light_client.py
new file mode 100644
index 000000000..15c764fc4
--- /dev/null
+++ b/tests/core/pyspec/eth2spec/test/helpers/light_client.py
@@ -0,0 +1,35 @@
+from eth2spec.test.helpers.sync_committee import (
+    compute_aggregate_sync_committee_signature,
+)
+
+
+def initialize_light_client_store(spec, state):
+    return spec.LightClientStore(
+        finalized_header=spec.BeaconBlockHeader(),
+        current_sync_committee=state.current_sync_committee,
+        next_sync_committee=state.next_sync_committee,
+        best_valid_update=None,
+        optimistic_header=spec.BeaconBlockHeader(),
+        previous_max_active_participants=0,
+        current_max_active_participants=0,
+    )
+
+
+def get_sync_aggregate(spec, state, block_header, block_root=None, signature_slot=None):
+    if signature_slot is None:
+        signature_slot = block_header.slot
+
+    all_pubkeys = [v.pubkey for v in state.validators]
+    committee = [all_pubkeys.index(pubkey) for pubkey in state.current_sync_committee.pubkeys]
+    sync_committee_bits = [True] * len(committee)
+    sync_committee_signature = compute_aggregate_sync_committee_signature(
+        spec,
+        state,
+        block_header.slot,
+        committee,
+        block_root=block_root,
+    )
+    return spec.SyncAggregate(
+        sync_committee_bits=sync_committee_bits,
+        sync_committee_signature=sync_committee_signature,
+    )