diff --git a/specs/validator/0_beacon-chain-validator.md b/specs/validator/0_beacon-chain-validator.md
index 6fdeafb49..1379e49ae 100644
--- a/specs/validator/0_beacon-chain-validator.md
+++ b/specs/validator/0_beacon-chain-validator.md
@@ -262,7 +262,9 @@ Set `attestation_data.beacon_block_root = hash_tree_root(head)` where `head` is
 
 Set `attestation_data.epoch_boundary_root = hash_tree_root(epoch_boundary)` where `epoch_boundary` is the block at the most recent epoch boundary in the chain defined by `head` -- i.e. the `BeaconBlock` where `block.slot == get_epoch_start_slot(slot_to_epoch(head.slot))`.
 
-_Note:_ This can be looked up in the state using `get_block_root(state, get_epoch_start_slot(slot_to_epoch(head.slot)))`.
+_Note:_ This can be looked up in the state using:
+* Let `epoch_start_slot = get_epoch_start_slot(slot_to_epoch(head.slot))`. `get_block_root(state, get_epoch_start_slot(slot_to_epoch(head.slot)))`.
+* Set `epoch_boundary_root = hash_tree_root(head) if epoch_start_slot == head.slot else get_block_root(state, epoch_start_slot)`.
 
 ##### Shard block root