diff --git a/chaind_eth/chain.py b/chaind_eth/chain.py
index d9171cd..687a802 100644
--- a/chaind_eth/chain.py
+++ b/chaind_eth/chain.py
@@ -9,6 +9,7 @@ from chainlib.eth.tx import (
         Tx,
         )
 
+
 class EthChainInterface(ChainInterface):
 
     def __init__(self):
diff --git a/tests/chaind_eth_base.py b/tests/chaind_eth_base.py
index 33a9a09..e83cd0d 100644
--- a/tests/chaind_eth_base.py
+++ b/tests/chaind_eth_base.py
@@ -6,6 +6,9 @@ from chainsyncer.unittest.db import ChainSyncerDb
 from chainqueue.unittest.db import ChainQueueDb
 from chainlib.eth.unittest.ethtester import EthTesterCase
 
+# local imports
+from chaind_eth.chain import EthChainInterface
+
 
 class TestBase(EthTesterCase):
 
@@ -17,6 +20,8 @@ class TestBase(EthTesterCase):
         self.db_chainqueue = ChainQueueDb()
         self.session_chainqueue = self.db_chainqueue.bind_session()
 
+        self.interface = EthChainInterface()
+
     def tearDown(self):
         self.session_chainsyncer.commit()
         self.db_chainsyncer.release_session(self.session_chainsyncer)
diff --git a/tests/test_chain.py b/tests/test_chain.py
new file mode 100644
index 0000000..0d13820
--- /dev/null
+++ b/tests/test_chain.py
@@ -0,0 +1,38 @@
+# standard imports
+import unittest
+
+# external imports
+from chainlib.eth.gas import (
+        RPCGasOracle,
+        Gas,
+        )
+from chainlib.eth.nonce import (
+        RPCNonceOracle,
+        )
+from chainlib.eth.tx import (
+        TxFormat,
+        unpack,
+        )
+from hexathon import (
+        strip_0x,
+        )
+
+# test imports
+from tests.chaind_eth_base import TestBase
+
+class TestChain(TestBase):
+
+    def test_chain_interface(self):
+        gas_oracle = RPCGasOracle(conn=self.rpc)
+        nonce_oracle = RPCNonceOracle(self.accounts[0], conn=self.rpc)
+        c = Gas(self.chain_spec, signer=self.signer, gas_oracle=gas_oracle, nonce_oracle=nonce_oracle)
+        (tx_hash, tx_raw_rlp_signed) = c.create(self.accounts[0], self.accounts[1], 1024, tx_format=TxFormat.RLP_SIGNED)
+
+        tx_raw_rlp_signed_bytes = bytes.fromhex(strip_0x(tx_raw_rlp_signed))
+        tx_src = unpack(tx_raw_rlp_signed_bytes, self.chain_spec)
+        tx_src = self.interface.src_normalize(tx_src)
+        assert tx_src['gas_price'] == tx_src['gasPrice']
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/tests/test_filter.py b/tests/test_filter.py
index 6e6e0ae..a78de29 100644
--- a/tests/test_filter.py
+++ b/tests/test_filter.py
@@ -40,10 +40,9 @@ from chainqueue.sql.state import (
         set_ready,
         )
 
-
-
 # local imports
 from chaind_eth.filter import StateFilter
+from chaind_eth.chain import EthChainInterface
 
 # test imports
 from tests.chaind_eth_base import TestBase
@@ -62,12 +61,15 @@ class TestFilter(TestBase):
         o = raw(tx_raw_rlp_signed)
         self.rpc.do(o)
 
-        o = receipt(tx_hash)
+        #o = receipt(tx_hash)
+        o = self.interface.tx_receipt(tx_hash)
         rcpt = self.rpc.do(o)
 
-        o = block_by_hash(rcpt['block_hash'])
+        #o = block_by_hash(rcpt['block_hash'])
+        o = self.interface.block_by_number(rcpt['block_number'])
         block_src = self.rpc.do(o)
-        block = Block(block_src)
+        #block = Block(block_src)
+        block = self.interface.block_from_src(block_src)
 
         dsn = dsn_from_config(db_config)
         backend = SQLBackend(dsn, debug=bool(os.environ.get('DATABASE_DEBUG')))
@@ -81,6 +83,7 @@ class TestFilter(TestBase):
         set_sent(self.chain_spec, tx_hash, session=self.session_chainqueue)      
 
         tx_src = unpack(tx_raw_rlp_signed_bytes, self.chain_spec)
+        tx_src = self.interface.src_normalize(tx_src)
         tx = Tx(tx_src, block=block, rcpt=rcpt)
 
         tx_repr = get_tx(self.chain_spec, tx_hash, session=self.session_chainqueue)