diff --git a/specs/phase0/fork-choice.md b/specs/phase0/fork-choice.md
index ca38926fc..de0a2e785 100644
--- a/specs/phase0/fork-choice.md
+++ b/specs/phase0/fork-choice.md
@@ -181,15 +181,19 @@ def get_latest_attesting_balance(store: Store, root: Root) -> Gwei:
         if (i in store.latest_messages
             and get_ancestor(store, store.latest_messages[i].root, store.blocks[root].slot) == root)
     ))
+    if store.proposer_boost_root == Root():
+        # Return only attestation score if ``proposer_boost_root`` is not set
+        return attestation_score
+
+    # Calculate proposer score if ``proposer_boost_root`` is set
     proposer_score = Gwei(0)
-    if store.proposer_boost_root != Root():
-        block = store.blocks[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
-            committee_weight = committee_size * avg_balance
-            proposer_score = (committee_weight * PROPOSER_SCORE_BOOST) // 100
+    # Boost is applied if ``root`` is an ancestor of ``proposer_boost_root``
+    if get_ancestor(store, store.proposer_boost_root, store.blocks[root].slot) == 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
+        committee_weight = committee_size * avg_balance
+        proposer_score = (committee_weight * PROPOSER_SCORE_BOOST) // 100
     return attestation_score + proposer_score
 
 ```
diff --git a/specs/sharding/beacon-chain.md b/specs/sharding/beacon-chain.md
index 8190951b4..cf3d7bea1 100644
--- a/specs/sharding/beacon-chain.md
+++ b/specs/sharding/beacon-chain.md
@@ -101,7 +101,7 @@ The following values are (non-configurable) constants used throughout the specif
 
 | Name | Value | Notes |
 | - | - | - |
-| `PRIMITIVE_ROOT_OF_UNITY` | `5` | Primitive root of unity of the BLS12_381 (inner) modulus |
+| `PRIMITIVE_ROOT_OF_UNITY` | `7` | Primitive root of unity of the BLS12_381 (inner) modulus |
 | `DATA_AVAILABILITY_INVERSE_CODING_RATE` | `2**1` (= 2) | Factor by which samples are extended for data availability encoding |
 | `POINTS_PER_SAMPLE` | `uint64(2**3)` (= 8) | 31 * 8 = 248 bytes |
 | `MODULUS` | `0x73eda753299d7d483339d80809a1d80553bda402fffe5bfeffffffff00000001` (curve order of BLS12_381) |
diff --git a/tests/core/pyspec/eth2spec/test/phase0/fork_choice/test_get_head.py b/tests/core/pyspec/eth2spec/test/phase0/fork_choice/test_get_head.py
index d2c84fce7..a524cbd56 100644
--- a/tests/core/pyspec/eth2spec/test/phase0/fork_choice/test_get_head.py
+++ b/tests/core/pyspec/eth2spec/test/phase0/fork_choice/test_get_head.py
@@ -166,6 +166,9 @@ def test_shorter_chain_but_heavier_weight(spec, state):
     signed_short_block = state_transition_and_sign_block(spec, short_state, short_block)
     yield from tick_and_add_block(spec, store, signed_short_block, test_steps)
 
+    # Since the long chain has higher proposer_score at slot 1, the latest long block is the head
+    assert spec.get_head(store) == spec.hash_tree_root(long_block)
+
     short_attestation = get_valid_attestation(spec, short_state, short_block.slot, signed=True)
     yield from tick_and_run_on_attestation(spec, store, short_attestation, test_steps)