diff --git a/eth/tools/fixtures/helpers.py b/eth/tools/fixtures/helpers.py
index 4511e2320c..26bcd14a35 100644
--- a/eth/tools/fixtures/helpers.py
+++ b/eth/tools/fixtures/helpers.py
@@ -10,6 +10,9 @@
 
 from eth import MainnetChain
 from eth.db.atomic import AtomicDB
+from eth.tools.builder.chain import (
+    disable_pow_check,
+)
 from eth.utils.state import (
     diff_account_db,
 )
@@ -156,6 +159,9 @@ def new_chain_from_fixture(fixture, chain_cls=MainnetChain):
         vm_configuration=vm_config,
     )
 
+    if 'sealEngine' in fixture and fixture['sealEngine'] == 'NoProof':
+        ChainFromFixture = disable_pow_check(ChainFromFixture)
+
     return ChainFromFixture.from_genesis(
         base_db,
         genesis_params=genesis_params_from_fixture(fixture),
diff --git a/eth/tools/fixtures/normalization.py b/eth/tools/fixtures/normalization.py
index 8b80361001..89b78657ae 100644
--- a/eth/tools/fixtures/normalization.py
+++ b/eth/tools/fixtures/normalization.py
@@ -495,6 +495,9 @@ def normalize_blockchain_fixtures(fixture):
         'network': fixture['network'],
     }
 
+    if 'sealEngine' in fixture:
+        normalized_fixture['sealEngine'] = fixture['sealEngine']
+
     if 'genesisRLP' in fixture:
         normalized_fixture['genesisRLP'] = decode_hex(fixture['genesisRLP'])