diff --git a/specs/core/1_custody-game.md b/specs/core/1_custody-game.md
index 3fe132c07..b051d13c6 100644
--- a/specs/core/1_custody-game.md
+++ b/specs/core/1_custody-game.md
@@ -204,7 +204,7 @@ class EarlyDerivedSecretReveal(Container):
     # Index of the validator who revealed (whistleblower)
     masker_index: ValidatorIndex
     # Mask used to hide the actual reveal signature (prevent reveal from being stolen)
-    mask: Bytes32
+    mask: Hash
 ```
 
 ### Phase 0 container updates
diff --git a/test_libs/pyspec/eth2spec/test/helpers/custody.py b/test_libs/pyspec/eth2spec/test/helpers/custody.py
index 67df12fcd..0167edc6a 100644
--- a/test_libs/pyspec/eth2spec/test/helpers/custody.py
+++ b/test_libs/pyspec/eth2spec/test/helpers/custody.py
@@ -1,5 +1,5 @@
 from eth2spec.test.helpers.keys import privkeys
-from eth2spec.utils.bls import bls_sign
+from eth2spec.utils.bls import bls_sign, bls_aggregate_signatures
 
 
 def get_valid_early_derived_secret_reveal(spec, state, epoch=None):
@@ -10,6 +10,7 @@ def get_valid_early_derived_secret_reveal(spec, state, epoch=None):
     if epoch is None:
         epoch = current_epoch + spec.CUSTODY_PERIOD_TO_RANDAO_PADDING
 
+    # Generate the secret that is being revealed
     reveal = bls_sign(
         message_hash=spec.hash_tree_root(epoch),
         privkey=privkeys[revealed_index],
@@ -19,8 +20,11 @@ def get_valid_early_derived_secret_reveal(spec, state, epoch=None):
             message_epoch=epoch,
         ),
     )
-    mask = bls_sign(
-        message_hash=spec.hash_tree_root(epoch),
+    # Generate the mask (any random 32 bytes will do)
+    mask = reveal[:32]
+    # Generate masker's signature on the mask
+    masker_signature = bls_sign(
+        message_hash=mask,
         privkey=privkeys[masker_index],
         domain=spec.get_domain(
             state=state,
@@ -28,11 +32,12 @@ def get_valid_early_derived_secret_reveal(spec, state, epoch=None):
             message_epoch=epoch,
         ),
     )
+    masked_reveal = bls_aggregate_signatures([reveal, masker_signature])
 
     return spec.EarlyDerivedSecretReveal(
         revealed_index=revealed_index,
         epoch=epoch,
-        reveal=reveal,
+        reveal=masked_reveal,
         masker_index=masker_index,
         mask=mask,
     )
diff --git a/test_libs/pyspec/eth2spec/test/phase_1/block_processing/test_process_early_derived_secret_reveal.py b/test_libs/pyspec/eth2spec/test/phase_1/block_processing/test_process_early_derived_secret_reveal.py
index 87297d443..831ad35a5 100644
--- a/test_libs/pyspec/eth2spec/test/phase_1/block_processing/test_process_early_derived_secret_reveal.py
+++ b/test_libs/pyspec/eth2spec/test/phase_1/block_processing/test_process_early_derived_secret_reveal.py
@@ -1,7 +1,13 @@
 from eth2spec.test.helpers.custody import get_valid_early_derived_secret_reveal
 from eth2spec.test.helpers.block import apply_empty_block
 from eth2spec.test.helpers.state import next_epoch, get_balance
-from eth2spec.test.context import with_all_phases_except, spec_state_test, expect_assertion_error
+from eth2spec.test.context import (
+    with_all_phases_except,
+    spec_state_test,
+    expect_assertion_error,
+    always_bls,
+    never_bls,
+)
 
 
 def run_early_derived_secret_reveal_processing(spec, state, randao_key_reveal, valid=True):
@@ -36,6 +42,7 @@ def run_early_derived_secret_reveal_processing(spec, state, randao_key_reveal, v
 
 
 @with_all_phases_except(['phase0'])
+@always_bls
 @spec_state_test
 def test_success(spec, state):
     randao_key_reveal = get_valid_early_derived_secret_reveal(spec, state)
@@ -44,6 +51,7 @@ def test_success(spec, state):
 
 
 @with_all_phases_except(['phase0'])
+@never_bls
 @spec_state_test
 def test_reveal_from_current_epoch(spec, state):
     randao_key_reveal = get_valid_early_derived_secret_reveal(spec, state, spec.get_current_epoch(state))
@@ -52,6 +60,7 @@ def test_reveal_from_current_epoch(spec, state):
 
 
 @with_all_phases_except(['phase0'])
+@never_bls
 @spec_state_test
 def test_reveal_from_past_epoch(spec, state):
     next_epoch(spec, state)
@@ -62,6 +71,7 @@ def test_reveal_from_past_epoch(spec, state):
 
 
 @with_all_phases_except(['phase0'])
+@always_bls
 @spec_state_test
 def test_reveal_with_custody_padding(spec, state):
     randao_key_reveal = get_valid_early_derived_secret_reveal(
@@ -73,6 +83,7 @@ def test_reveal_with_custody_padding(spec, state):
 
 
 @with_all_phases_except(['phase0'])
+@always_bls
 @spec_state_test
 def test_reveal_with_custody_padding_minus_one(spec, state):
     randao_key_reveal = get_valid_early_derived_secret_reveal(
@@ -84,6 +95,7 @@ def test_reveal_with_custody_padding_minus_one(spec, state):
 
 
 @with_all_phases_except(['phase0'])
+@never_bls
 @spec_state_test
 def test_double_reveal(spec, state):
     randao_key_reveal1 = get_valid_early_derived_secret_reveal(
@@ -108,6 +120,7 @@ def test_double_reveal(spec, state):
 
 
 @with_all_phases_except(['phase0'])
+@never_bls
 @spec_state_test
 def test_revealer_is_slashed(spec, state):
     randao_key_reveal = get_valid_early_derived_secret_reveal(spec, state, spec.get_current_epoch(state))
@@ -117,6 +130,7 @@ def test_revealer_is_slashed(spec, state):
 
 
 @with_all_phases_except(['phase0'])
+@never_bls
 @spec_state_test
 def test_far_future_epoch(spec, state):
     randao_key_reveal = get_valid_early_derived_secret_reveal(