diff --git a/specs/bellatrix/fork-choice.md b/specs/bellatrix/fork-choice.md
index ed7d60a93..aac26f3dd 100644
--- a/specs/bellatrix/fork-choice.md
+++ b/specs/bellatrix/fork-choice.md
@@ -170,7 +170,7 @@ def on_block(store: Store, signed_block: SignedBeaconBlock) -> None:
     finalized_slot = compute_start_slot_at_epoch(store.finalized_checkpoint.epoch)
     assert block.slot > finalized_slot
     # Check block is a descendant of the finalized block at the checkpoint finalized slot
-    assert get_ancestor(store, block.parent_root, finalized_slot) == store.finalized_checkpoint.root
+    assert get_ancestor_at_epoch_boundary(store, block.parent_root, store.finalized_checkpoint.epoch) == store.finalized_checkpoint.root
 
     # Check the block is valid and compute the post-state
     state = pre_state.copy()
diff --git a/specs/deneb/fork-choice.md b/specs/deneb/fork-choice.md
index 61714cf1a..83cdb9972 100644
--- a/specs/deneb/fork-choice.md
+++ b/specs/deneb/fork-choice.md
@@ -82,7 +82,7 @@ def on_block(store: Store, signed_block: SignedBeaconBlock) -> None:
     finalized_slot = compute_start_slot_at_epoch(store.finalized_checkpoint.epoch)
     assert block.slot > finalized_slot
     # Check block is a descendant of the finalized block at the checkpoint finalized slot
-    assert get_ancestor(store, block.parent_root, finalized_slot) == store.finalized_checkpoint.root
+    assert get_ancestor_at_epoch_boundary(store, block.parent_root, store.finalized_checkpoint.epoch) == store.finalized_checkpoint.root
 
     # [New in Deneb]
     # Check if blob data is available