diff --git a/specs/merge/fork-choice.md b/specs/merge/fork-choice.md
index 7a8db7dd9..cbfe33f4a 100644
--- a/specs/merge/fork-choice.md
+++ b/specs/merge/fork-choice.md
@@ -178,10 +178,7 @@ def on_block(store: Store, signed_block: SignedBeaconBlock) -> None:
     # Add proposer score boost if the block is timely
     is_before_attesting_interval = store.time % SECONDS_PER_SLOT < SECONDS_PER_SLOT // INTERVALS_PER_SLOT
     if get_current_slot(store) == block.slot and is_before_attesting_interval:
-        store.proposer_score_boost = LatestMessage(
-            root=hash_tree_root(block),
-            epoch=compute_epoch_at_slot(block.slot)
-        )
+        store.proposer_boost_root = hash_tree_root(block)
 
     # Update justified checkpoint
     if state.current_justified_checkpoint.epoch > store.justified_checkpoint.epoch:
diff --git a/specs/phase0/fork-choice.md b/specs/phase0/fork-choice.md
index 9c27a423f..6e50b99d4 100644
--- a/specs/phase0/fork-choice.md
+++ b/specs/phase0/fork-choice.md
@@ -100,7 +100,7 @@ class Store(object):
     justified_checkpoint: Checkpoint
     finalized_checkpoint: Checkpoint
     best_justified_checkpoint: Checkpoint
-    proposer_score_boost: LatestMessage
+    proposer_boost_root: Root
     blocks: Dict[Root, BeaconBlock] = field(default_factory=dict)
     block_states: Dict[Root, BeaconState] = field(default_factory=dict)
     checkpoint_states: Dict[Checkpoint, BeaconState] = field(default_factory=dict)
@@ -121,14 +121,14 @@ def get_forkchoice_store(anchor_state: BeaconState, anchor_block: BeaconBlock) -
     anchor_epoch = get_current_epoch(anchor_state)
     justified_checkpoint = Checkpoint(epoch=anchor_epoch, root=anchor_root)
     finalized_checkpoint = Checkpoint(epoch=anchor_epoch, root=anchor_root)
-    proposer_score_boost = LatestMessage(root=Root(), epoch=Epoch(0))
+    proposer_boost_root = Root()
     return Store(
         time=uint64(anchor_state.genesis_time + SECONDS_PER_SLOT * anchor_state.slot),
         genesis_time=anchor_state.genesis_time,
         justified_checkpoint=justified_checkpoint,
         finalized_checkpoint=finalized_checkpoint,
         best_justified_checkpoint=justified_checkpoint,
-        proposer_score_boost=proposer_score_boost,
+        proposer_boost_root=proposer_boost_root,
         blocks={anchor_root: copy(anchor_block)},
         block_states={anchor_root: copy(anchor_state)},
         checkpoint_states={justified_checkpoint: copy(anchor_state)},
@@ -182,9 +182,9 @@ def get_latest_attesting_balance(store: Store, root: Root) -> Gwei:
             and get_ancestor(store, store.latest_messages[i].root, store.blocks[root].slot) == root)
     ))
     proposer_score = Gwei(0)
-    if store.proposer_score_boost.root != Root():
+    if store.proposer_boost_root != Root():
         block = store.blocks[root]
-        if get_ancestor(store, root, block.slot) == store.proposer_score_boost.root:
+        if get_ancestor(store, root, block.slot) == store.proposer_boost_root:
             num_validators = len(get_active_validator_indices(state, get_current_epoch(state)))
             avg_balance = get_total_active_balance(state) // num_validators
             committee_size = num_validators // SLOTS_PER_EPOCH
@@ -371,9 +371,9 @@ def on_tick(store: Store, time: uint64) -> None:
 
     current_slot = get_current_slot(store)
 
-    # Reset store.proposer_score_boost if this is a new slot
+    # Reset store.proposer_boost_root if this is a new slot
     if current_slot > previous_slot:
-        store.proposer_score_boost = LatestMessage(root=Root(), epoch=Epoch(0))
+        store.proposer_boost_root = Root()
 
     # Not a new epoch, return
     if not (current_slot > previous_slot and compute_slots_since_epoch_start(current_slot) == 0):
@@ -416,10 +416,7 @@ def on_block(store: Store, signed_block: SignedBeaconBlock) -> None:
     # Add proposer score boost if the block is timely
     is_before_attesting_interval = store.time % SECONDS_PER_SLOT < SECONDS_PER_SLOT // INTERVALS_PER_SLOT
     if get_current_slot(store) == block.slot and is_before_attesting_interval:
-        store.proposer_score_boost = LatestMessage(
-            root=hash_tree_root(block),
-            epoch=compute_epoch_at_slot(block.slot)
-        )
+        store.proposer_boost_root = hash_tree_root(block)
 
     # Update justified checkpoint
     if state.current_justified_checkpoint.epoch > store.justified_checkpoint.epoch:
diff --git a/tests/core/pyspec/eth2spec/test/phase0/fork_choice/test_on_block.py b/tests/core/pyspec/eth2spec/test/phase0/fork_choice/test_on_block.py
index c4c9fffc1..f234125e0 100644
--- a/tests/core/pyspec/eth2spec/test/phase0/fork_choice/test_on_block.py
+++ b/tests/core/pyspec/eth2spec/test/phase0/fork_choice/test_on_block.py
@@ -707,7 +707,56 @@ def test_new_finalized_slot_is_justified_checkpoint_ancestor(spec, state):
 
 @with_all_phases
 @spec_state_test
-def test_proposer_score_boost_same_slot_untimely_block(spec, state):
+def test_proposer_boost(spec, state):
+    test_steps = []
+    genesis_state = state.copy()
+
+    # Initialization
+    store, anchor_block = get_genesis_forkchoice_store_and_block(spec, state)
+    yield 'anchor_state', state
+    yield 'anchor_block', anchor_block
+
+    # Build block that serves as head ONLY on timely arrival, and ONLY in that slot
+    state = genesis_state.copy()
+    next_slots(spec, state, 3)
+    block = build_empty_block_for_next_slot(spec, state)
+    signed_block = state_transition_and_sign_block(spec, state, block)
+
+    # Process block on timely arrival just before end of boost interval
+    spec.on_tick(store, store.genesis_time + block.slot * spec.config.SECONDS_PER_SLOT +
+                 spec.config.SECONDS_PER_SLOT // spec.INTERVALS_PER_SLOT - 1)
+    yield from tick_and_add_block(spec, store, signed_block, test_steps)
+    assert store.proposer_boost_root == spec.hash_tree_root(block)
+    assert spec.get_latest_attesting_balance(store, spec.hash_tree_root(block)) > 0
+
+    # Ensure that boost is removed after slot is over
+    spec.on_tick(store, store.genesis_time + block.slot * spec.config.SECONDS_PER_SLOT +
+                 spec.config.SECONDS_PER_SLOT)
+    assert store.proposer_boost_root == spec.Root()
+    assert spec.get_latest_attesting_balance(store, spec.hash_tree_root(block)) == 0
+
+    next_slots(spec, state, 3)
+    block = build_empty_block_for_next_slot(spec, state)
+    signed_block = state_transition_and_sign_block(spec, state, block)
+
+    # Process block on timely arrival at start of boost interval
+    spec.on_tick(store, store.genesis_time + block.slot * spec.config.SECONDS_PER_SLOT)
+    yield from tick_and_add_block(spec, store, signed_block, test_steps)
+    assert store.proposer_boost_root == spec.hash_tree_root(block)
+    assert spec.get_latest_attesting_balance(store, spec.hash_tree_root(block)) > 0
+
+    # Ensure that boost is removed after slot is over
+    spec.on_tick(store, store.genesis_time + block.slot * spec.config.SECONDS_PER_SLOT +
+                 spec.config.SECONDS_PER_SLOT)
+    assert store.proposer_boost_root == spec.Root()
+    assert spec.get_latest_attesting_balance(store, spec.hash_tree_root(block)) == 0
+
+    yield 'steps', test_steps
+
+
+@with_all_phases
+@spec_state_test
+def test_proposer_boost_root_same_slot_untimely_block(spec, state):
     test_steps = []
     genesis_state = state.copy()
 
@@ -726,6 +775,6 @@ def test_proposer_score_boost_same_slot_untimely_block(spec, state):
     spec.on_tick(store, store.genesis_time + block.slot * spec.config.SECONDS_PER_SLOT +
                  spec.config.SECONDS_PER_SLOT // spec.INTERVALS_PER_SLOT)
     yield from tick_and_add_block(spec, store, signed_block, test_steps)
-    assert store.proposer_score_boost.root == spec.Root()
+    assert store.proposer_boost_root == spec.Root()
 
     yield 'steps', test_steps