diff --git a/python/eth_contract_registry/pytest/fixtures_registry.py b/python/eth_contract_registry/pytest/fixtures_registry.py
index 64afa31..2458646 100644
--- a/python/eth_contract_registry/pytest/fixtures_registry.py
+++ b/python/eth_contract_registry/pytest/fixtures_registry.py
@@ -45,7 +45,7 @@ def registry(
   
     nonce_oracle = RPCNonceOracle(roles['CONTRACT_DEPLOYER'], eth_rpc)
 
-    builder = Registry(signer=eth_signer, nonce_oracle=nonce_oracle)
+    builder = Registry(default_chain_spec, signer=eth_signer, nonce_oracle=nonce_oracle)
     logg.info('registering identifiers {} in contract registry'.format(valid_identifiers))
     (tx_hash_hex, o) = builder.constructor(roles['CONTRACT_DEPLOYER'], valid_identifiers)
     r = eth_rpc.do(o)
@@ -56,7 +56,7 @@ def registry(
 
     registry_address = rcpt['contract_address'] 
 
-    c = Registry(signer=eth_signer, nonce_oracle=nonce_oracle)
+    c = Registry(default_chain_spec, signer=eth_signer, nonce_oracle=nonce_oracle)
 
     chain_spec_identifier = to_identifier(str(default_chain_spec))
 
diff --git a/python/setup.cfg b/python/setup.cfg
index 4b9be2d..64e560c 100644
--- a/python/setup.cfg
+++ b/python/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = eth-contract-registry
-version = 0.5.4a7
+version = 0.5.4a8
 description = Ethereum Smart Contract key-value registry
 author = Louis Holbrook
 author_email = dev@holbrook.no