diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index 865c4c175..ecbcdebb1 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -1526,13 +1526,17 @@ For each `attestation` in `block.body.attestations`:
 * Verify that `attestation.data.justified_slot` is equal to `state.justified_slot if attestation.data.slot >= state.slot - (state.slot % EPOCH_LENGTH) else state.previous_justified_slot`.
 * Verify that `attestation.data.justified_block_root` is equal to `get_block_root(state, attestation.data.justified_slot)`.
 * Verify that either `attestation.data.latest_crosslink_root` or `attestation.data.shard_block_root` equals `state.latest_crosslinks[shard].shard_block_root`.
-* `attestation.aggregate_signature` verification:
+* Verify bitfields:
 
 ```python
     assert verify_bitfield(attestation.aggregation_bitfield)
     assert verify_bitfield(attestation.custody_bitfield)
     assert attestation.custody_bitfield & attestation.aggregation_bitfield == attestation.custody_bitfield
+```
 
+* Verify aggregate signature:
+
+```python
     participants = get_attestation_participants(state, attestation.data, attestation.aggregation_bitfield)
     custody_bit_0_participants = get_attestation_participants(state, attestation.data, attestation.custody_bitfield)
     custody_bit_1_participants = [i in participants for i not in custody_bit_0_participants]