diff --git a/specs/phase1/custody-game.md b/specs/phase1/custody-game.md
index 8774dc337..8d9c89c56 100644
--- a/specs/phase1/custody-game.md
+++ b/specs/phase1/custody-game.md
@@ -516,12 +516,8 @@ def process_custody_slashing(state: BeaconState, signed_custody_slashing: Signed
     shard_transition = custody_slashing.shard_transition
     assert hash_tree_root(shard_transition) == attestation.data.shard_transition_root
     # Verify that the provided data matches the shard-transition
-    assert (
-        hash_tree_root(custody_slashing.data)
-        == shard_transition.shard_data_roots[custody_slashing.data_index]
-    )
     assert len(custody_slashing.data) == shard_transition.shard_block_lengths[custody_slashing.data_index]
-
+    assert hash_tree_root(custody_slashing.data) == shard_transition.shard_data_roots[custody_slashing.data_index]
     # Verify existence and participation of claimed malefactor
     attesters = get_attesting_indices(state, attestation.data, attestation.aggregation_bits)
     assert custody_slashing.malefactor_index in attesters
diff --git a/tests/core/pyspec/eth2spec/test/helpers/custody.py b/tests/core/pyspec/eth2spec/test/helpers/custody.py
index c1e493931..162ca3263 100644
--- a/tests/core/pyspec/eth2spec/test/helpers/custody.py
+++ b/tests/core/pyspec/eth2spec/test/helpers/custody.py
@@ -150,7 +150,7 @@ def get_valid_custody_chunk_response(spec, state, chunk_challenge, challenge_ind
     chunk_index = chunk_challenge.chunk_index
 
     leaf_index = chunk_index + 2**spec.CUSTODY_RESPONSE_DEPTH
-    serialized_length = (len(custody_data_block)).to_bytes(32, 'little')
+    serialized_length = len(custody_data_block).to_bytes(32, 'little')
     data_branch = build_proof(custody_data_block.get_backing().get_left(), leaf_index) + [serialized_length]
 
     return spec.CustodyChunkResponse(