diff --git a/specs/phase1/beacon-chain.md b/specs/phase1/beacon-chain.md
index fe5c0d9a7..c30810864 100644
--- a/specs/phase1/beacon-chain.md
+++ b/specs/phase1/beacon-chain.md
@@ -540,8 +540,12 @@ def is_valid_indexed_attestation(state: BeaconState, indexed_attestation: Indexe
                 if abit:
                     all_pubkeys.append(state.validators[participant].pubkey)
                     # Note: only 2N distinct message hashes
-                    all_signing_roots.append(compute_signing_root(
-                        AttestationCustodyBitWrapper(hash_tree_root(attestation.data), i, cbit), domain))
+                    attestation_wrapper = AttestationCustodyBitWrapper(
+                        attestation_data_root=hash_tree_root(attestation.data),
+                        block_index=i,
+                        bit=cbit
+                    )
+                    all_signing_roots.append(compute_signing_root(attestation_wrapper, domain))
                 else:
                     assert not cbit
         return bls.AggregateVerify(zip(all_pubkeys, all_signing_roots), signature=attestation.signature)
@@ -801,6 +805,7 @@ def get_indices_from_committee(
 def process_attester_slashing(state: BeaconState, attester_slashing: AttesterSlashing) -> None:
     indexed_attestation_1 = attester_slashing.attestation_1
     indexed_attestation_2 = attester_slashing.attestation_2
+
     assert is_slashable_attestation_data(
         indexed_attestation_1.attestation.data,
         indexed_attestation_2.attestation.data,
diff --git a/tests/core/pyspec/eth2spec/test/helpers/attestations.py b/tests/core/pyspec/eth2spec/test/helpers/attestations.py
index deebd0356..fea4ea1f6 100644
--- a/tests/core/pyspec/eth2spec/test/helpers/attestations.py
+++ b/tests/core/pyspec/eth2spec/test/helpers/attestations.py
@@ -202,9 +202,9 @@ def get_attestation_custody_signature(spec, state, attestation_data, block_index
     domain = spec.get_domain(state, spec.DOMAIN_BEACON_ATTESTER, attestation_data.target.epoch)
     signing_root = spec.compute_signing_root(
         spec.AttestationCustodyBitWrapper(
-            attestation_data.hash_tree_root(),
-            block_index,
-            bit,
+            attestation_data_root=attestation_data.hash_tree_root(),
+            block_index=block_index,
+            bit=bit,
         ),
         domain,
     )
diff --git a/tests/core/pyspec/eth2spec/test/phase_0/block_processing/test_process_attester_slashing.py b/tests/core/pyspec/eth2spec/test/phase_0/block_processing/test_process_attester_slashing.py
index c379bb815..e9665e714 100644
--- a/tests/core/pyspec/eth2spec/test/phase_0/block_processing/test_process_attester_slashing.py
+++ b/tests/core/pyspec/eth2spec/test/phase_0/block_processing/test_process_attester_slashing.py
@@ -143,10 +143,6 @@ def test_invalid_sig_1(spec, state):
 @always_bls
 def test_invalid_sig_2(spec, state):
     attester_slashing = get_valid_attester_slashing(spec, state, signed_1=True, signed_2=False)
-    """
-    SOMETHING WRONG WITH HASH CACHE OF SEPARATE ATTESTATIONS MAKING SIGS
-    LOOK CORRECT
-    """
     yield from run_attester_slashing_processing(spec, state, attester_slashing, False)