diff --git a/src/error.rs b/src/error.rs
index 24b0cc87e..fbe57a98b 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -1,6 +1,8 @@
 //! General error types for use in ethcore.
 
-use rustc_serialize::hex::*;
+use rustc_serialize::hex::FromHexError;
+use network::NetworkError;
+use rlp::DecoderError;
 
 #[derive(Debug)]
 pub enum BaseDataError {
@@ -9,22 +11,58 @@ pub enum BaseDataError {
 
 #[derive(Debug)]
 /// General error type which should be capable of representing all errors in ethcore.
-pub enum EthcoreError {
+pub enum UtilError {
+	Crypto(::crypto::CryptoError),
+	Io(::std::io::Error),
+	AddressParse(::std::net::AddrParseError),
+	AddressResolve(Option<::std::io::Error>),
 	FromHex(FromHexError),
 	BaseData(BaseDataError),
+	Network(NetworkError),
+	Decoder(DecoderError),
 	BadSize,
 	UnknownName,
 }
 
-impl From<FromHexError> for EthcoreError {
-	fn from(err: FromHexError) -> EthcoreError {
-		EthcoreError::FromHex(err)
+impl From<FromHexError> for UtilError {
+	fn from(err: FromHexError) -> UtilError {
+		UtilError::FromHex(err)
 	}
 }
 
-impl From<BaseDataError> for EthcoreError {
-	fn from(err: BaseDataError) -> EthcoreError {
-		EthcoreError::BaseData(err)
+impl From<BaseDataError> for UtilError {
+	fn from(err: BaseDataError) -> UtilError {
+		UtilError::BaseData(err)
+	}
+}
+
+impl From<NetworkError> for UtilError {
+	fn from(err: NetworkError) -> UtilError {
+		UtilError::Network(err)
+	}
+}
+
+impl From<::std::io::Error> for UtilError {
+	fn from(err: ::std::io::Error) -> UtilError {
+		UtilError::Io(err)
+	}
+}
+
+impl From<::crypto::CryptoError> for UtilError {
+	fn from(err: ::crypto::CryptoError) -> UtilError {
+		UtilError::Crypto(err)
+	}
+}
+
+impl From<::std::net::AddrParseError> for UtilError {
+	fn from(err: ::std::net::AddrParseError) -> UtilError {
+		UtilError::AddressParse(err)
+	}
+}
+
+impl From<::rlp::DecoderError> for UtilError {
+	fn from(err: ::rlp::DecoderError) -> UtilError {
+		UtilError::Decoder(err)
 	}
 }
 
@@ -32,9 +70,9 @@ impl From<BaseDataError> for EthcoreError {
 /*#![feature(concat_idents)]
 macro_rules! assimilate {
     ($name:ident) => (
-		impl From<concat_idents!($name, Error)> for EthcoreError {
-			fn from(err: concat_idents!($name, Error)) -> EthcoreError {
-				EthcoreError:: $name (err)
+		impl From<concat_idents!($name, Error)> for Error {
+			fn from(err: concat_idents!($name, Error)) -> Error {
+				Error:: $name (err)
 			}
 		}
     )
diff --git a/src/hash.rs b/src/hash.rs
index e368e064a..087454ceb 100644
--- a/src/hash.rs
+++ b/src/hash.rs
@@ -7,7 +7,7 @@ use std::hash::{Hash, Hasher};
 use std::ops::{Index, IndexMut, Deref, DerefMut, BitOr, BitOrAssign, BitAnd, BitXor};
 use std::cmp::{PartialOrd, Ordering};
 use rustc_serialize::hex::*;
-use error::EthcoreError;
+use error::UtilError;
 use rand::Rng;
 use rand::os::OsRng;
 use bytes::{BytesConvertable,Populatable};
@@ -176,11 +176,10 @@ macro_rules! impl_hash {
 		}
 
 		impl FromStr for $from {
-			type Err = EthcoreError;
-
-			fn from_str(s: &str) -> Result<$from, EthcoreError> {
+			type Err = UtilError;
+			fn from_str(s: &str) -> Result<$from, UtilError> {
 				let a = try!(s.from_hex());
-				if a.len() != $size { return Err(EthcoreError::BadSize); }
+				if a.len() != $size { return Err(UtilError::BadSize); }
 				let mut ret = $from([0;$size]);
 				for i in 0..$size {
 					ret.0[i] = a[i];
diff --git a/src/network/connection.rs b/src/network/connection.rs
index 2a8025b83..2db53c11e 100644
--- a/src/network/connection.rs
+++ b/src/network/connection.rs
@@ -7,7 +7,8 @@ use bytes::*;
 use rlp::*;
 use std::io::{self, Cursor, Read};
 use network::host::{Host};
-use network::Error;
+use error::*;
+use network::NetworkError;
 use network::handshake::Handshake;
 use crypto;
 use rcrypto::blockmodes::*;
@@ -158,7 +159,7 @@ pub struct EncryptedConnection {
 }
 
 impl EncryptedConnection {
-	pub fn new(handshake: Handshake) -> Result<EncryptedConnection, Error> {
+	pub fn new(handshake: Handshake) -> Result<EncryptedConnection, UtilError> {
 		let shared = try!(crypto::ecdh::agree(handshake.ecdhe.secret(), &handshake.remote_public));
 		let mut nonce_material = H512::new();
 		if handshake.originated {
@@ -207,7 +208,7 @@ impl EncryptedConnection {
 		})
 	}
 
-	pub fn send_packet(&mut self, payload: &[u8]) -> Result<(), Error> {
+	pub fn send_packet(&mut self, payload: &[u8]) -> Result<(), UtilError> {
 		let mut header = RlpStream::new();
 		let len = payload.len() as usize;
 		header.append_raw(&[(len >> 16) as u8, (len >> 8) as u8, len as u8], 1);
@@ -233,16 +234,16 @@ impl EncryptedConnection {
 		Ok(())
 	}
 
-	fn read_header(&mut self, header: &[u8]) -> Result<(), Error> {
+	fn read_header(&mut self, header: &[u8]) -> Result<(), UtilError> {
 		if header.len() != ENCRYPTED_HEADER_LEN {
-			return Err(Error::Auth);
+			return Err(From::from(NetworkError::Auth));
 		}
 		EncryptedConnection::update_mac(&mut self.ingress_mac, &mut self.mac_encoder, &header[0..16]);
 		let mac = &header[16..];
 		let mut expected = H256::new();
 		self.ingress_mac.clone().finalize(&mut expected);
 		if mac != &expected[0..16] {
-			return Err(Error::Auth);
+			return Err(From::from(NetworkError::Auth));
 		}
 
 		let mut hdec = H128::new();
@@ -262,11 +263,11 @@ impl EncryptedConnection {
 		Ok(())
 	}
 
-	fn read_payload(&mut self, payload: &[u8]) -> Result<Packet, Error> {
+	fn read_payload(&mut self, payload: &[u8]) -> Result<Packet, UtilError> {
 		let padding = (16 - (self.payload_len  % 16)) % 16;
 		let full_length = (self.payload_len + padding + 16) as usize;
 		if payload.len() != full_length {
-			return Err(Error::Auth);
+			return Err(From::from(NetworkError::Auth));
 		}
 		self.ingress_mac.update(&payload[0..payload.len() - 16]);
 		EncryptedConnection::update_mac(&mut self.ingress_mac, &mut self.mac_encoder, &[0u8; 0]);
@@ -274,7 +275,7 @@ impl EncryptedConnection {
 		let mut expected = H128::new();
 		self.ingress_mac.clone().finalize(&mut expected);
 		if mac != &expected[..] {
-			return Err(Error::Auth);
+			return Err(From::from(NetworkError::Auth));
 		}
 
 		let mut packet = vec![0u8; self.payload_len as usize];
@@ -297,7 +298,7 @@ impl EncryptedConnection {
 		mac.update(&enc);
 	}
 
-	pub fn readable(&mut self, event_loop: &mut EventLoop<Host>) -> Result<Option<Packet>, Error> {
+	pub fn readable(&mut self, event_loop: &mut EventLoop<Host>) -> Result<Option<Packet>, UtilError> {
 		self.idle_timeout.map(|t| event_loop.clear_timeout(t));
 		try!(self.connection.reregister(event_loop));
 		match self.read_state {
@@ -323,14 +324,14 @@ impl EncryptedConnection {
 		}
 	}
 
-	pub fn writable(&mut self, event_loop: &mut EventLoop<Host>) -> Result<(), Error> {
+	pub fn writable(&mut self, event_loop: &mut EventLoop<Host>) -> Result<(), UtilError> {
 		self.idle_timeout.map(|t| event_loop.clear_timeout(t));
 		try!(self.connection.writable());
 		try!(self.connection.reregister(event_loop));
 		Ok(())
 	}
 
-	pub fn register(&mut self, event_loop: &mut EventLoop<Host>) -> Result<(), Error> {
+	pub fn register(&mut self, event_loop: &mut EventLoop<Host>) -> Result<(), UtilError> {
 		self.connection.expect(ENCRYPTED_HEADER_LEN);
 		self.idle_timeout.map(|t| event_loop.clear_timeout(t));
 		self.idle_timeout = event_loop.timeout_ms(self.connection.token, 1800).ok();
diff --git a/src/network/handshake.rs b/src/network/handshake.rs
index 4df8cbe8b..d9e280bfe 100644
--- a/src/network/handshake.rs
+++ b/src/network/handshake.rs
@@ -7,7 +7,8 @@ use crypto::*;
 use crypto;
 use network::connection::{Connection};
 use network::host::{NodeId, Host, HostInfo};
-use network::Error;
+use error::*;
+use network::NetworkError;
 
 #[derive(PartialEq, Eq, Debug)]
 enum HandshakeState {
@@ -35,7 +36,7 @@ const AUTH_PACKET_SIZE: usize = 307;
 const ACK_PACKET_SIZE: usize = 210;
 
 impl Handshake {
-	pub fn new(token: Token, id: &NodeId, socket: TcpStream, nonce: &H256) -> Result<Handshake, Error> {
+	pub fn new(token: Token, id: &NodeId, socket: TcpStream, nonce: &H256) -> Result<Handshake, UtilError> {
 		Ok(Handshake {
 			id: id.clone(),
 			connection: Connection::new(token, socket),
@@ -51,7 +52,7 @@ impl Handshake {
 		})
 	}
 
-	pub fn start(&mut self, host: &HostInfo, originated: bool) -> Result<(), Error> {
+	pub fn start(&mut self, host: &HostInfo, originated: bool) -> Result<(), UtilError> {
 		self.originated = originated;
 		if originated {
 			try!(self.write_auth(host));
@@ -67,7 +68,7 @@ impl Handshake {
 		self.state == HandshakeState::StartSession
 	}
 
-	pub fn readable(&mut self, event_loop: &mut EventLoop<Host>, host: &HostInfo) -> Result<(), Error> {
+	pub fn readable(&mut self, event_loop: &mut EventLoop<Host>, host: &HostInfo) -> Result<(), UtilError> {
 		self.idle_timeout.map(|t| event_loop.clear_timeout(t));
 		match self.state {
 			HandshakeState::ReadingAuth => {
@@ -96,7 +97,7 @@ impl Handshake {
 		Ok(())
 	}
 
-	pub fn writable(&mut self, event_loop: &mut EventLoop<Host>, _host: &HostInfo) -> Result<(), Error> {
+	pub fn writable(&mut self, event_loop: &mut EventLoop<Host>, _host: &HostInfo) -> Result<(), UtilError> {
 		self.idle_timeout.map(|t| event_loop.clear_timeout(t));
 		try!(self.connection.writable());
 		if self.state != HandshakeState::StartSession {
@@ -105,14 +106,14 @@ impl Handshake {
 		Ok(())
 	}
 
-	pub fn register(&mut self, event_loop: &mut EventLoop<Host>) -> Result<(), Error> {
+	pub fn register(&mut self, event_loop: &mut EventLoop<Host>) -> Result<(), UtilError> {
 		self.idle_timeout.map(|t| event_loop.clear_timeout(t));
 		self.idle_timeout = event_loop.timeout_ms(self.connection.token, 1800).ok();
 		try!(self.connection.register(event_loop));
 		Ok(())
 	}
 
-	fn read_auth(&mut self, host: &HostInfo, data: &[u8]) -> Result<(), Error> {
+	fn read_auth(&mut self, host: &HostInfo, data: &[u8]) -> Result<(), UtilError> {
 		trace!(target:"net", "Received handshake auth to {:?}", self.connection.socket.peer_addr());
 		assert!(data.len() == AUTH_PACKET_SIZE);
 		self.auth_cipher = data.to_vec();
@@ -128,12 +129,12 @@ impl Handshake {
 		let spub = try!(ec::recover(&signature, &(&shared ^ &self.remote_nonce)));
 		if &spub.sha3()[..] != hepubk {
 			trace!(target:"net", "Handshake hash mismath with {:?}", self.connection.socket.peer_addr());
-			return Err(Error::Auth);
+			return Err(From::from(NetworkError::Auth));
 		};
 		self.write_ack()
 	}
 
-	fn read_ack(&mut self, host: &HostInfo, data: &[u8]) -> Result<(), Error> {
+	fn read_ack(&mut self, host: &HostInfo, data: &[u8]) -> Result<(), UtilError> {
 		trace!(target:"net", "Received handshake auth to {:?}", self.connection.socket.peer_addr());
 		assert!(data.len() == ACK_PACKET_SIZE);
 		self.ack_cipher = data.to_vec();
@@ -143,7 +144,7 @@ impl Handshake {
 		Ok(())
 	}
 
-	fn write_auth(&mut self, host: &HostInfo) -> Result<(), Error> {
+	fn write_auth(&mut self, host: &HostInfo) -> Result<(), UtilError> {
 		trace!(target:"net", "Sending handshake auth to {:?}", self.connection.socket.peer_addr());
 		let mut data = [0u8; /*Signature::SIZE*/ 65 + /*H256::SIZE*/ 32 + /*Public::SIZE*/ 64 + /*H256::SIZE*/ 32 + 1]; //TODO: use associated constants
 		let len = data.len();
@@ -169,7 +170,7 @@ impl Handshake {
 		Ok(())
 	}
 
-	fn write_ack(&mut self) -> Result<(), Error> {
+	fn write_ack(&mut self) -> Result<(), UtilError> {
 		trace!(target:"net", "Sending handshake ack to {:?}", self.connection.socket.peer_addr());
 		let mut data = [0u8; 1 + /*Public::SIZE*/ 64 + /*H256::SIZE*/ 32]; //TODO: use associated constants
 		let len = data.len();
diff --git a/src/network/host.rs b/src/network/host.rs
index 9e2b3e101..243813b63 100644
--- a/src/network/host.rs
+++ b/src/network/host.rs
@@ -13,7 +13,8 @@ use rlp::*;
 use time::Tm;
 use network::handshake::Handshake;
 use network::session::{Session, SessionData};
-use network::{Error, ProtocolHandler};
+use error::*;
+use network::ProtocolHandler;
 
 const _DEFAULT_PORT: u16 = 30304;
 
@@ -53,7 +54,7 @@ pub struct NodeEndpoint {
 }
 
 impl NodeEndpoint {
-	fn from_str(s: &str) -> Result<NodeEndpoint, Error> {
+	fn from_str(s: &str) -> Result<NodeEndpoint, UtilError> {
 		let address = s.to_socket_addrs().map(|mut i| i.next());
 		match address {
 			Ok(Some(a)) => Ok(NodeEndpoint {
@@ -61,8 +62,8 @@ impl NodeEndpoint {
 				address_str: s.to_string(),
 				udp_port: a.port()
 			}),
-			Ok(_) => Err(Error::AddressResolve(None)),
-			Err(e) => Err(Error::AddressResolve(Some(e)))
+			Ok(_) => Err(UtilError::AddressResolve(None)),
+			Err(e) => Err(UtilError::AddressResolve(Some(e)))
 		}
 	}
 }
@@ -81,7 +82,7 @@ struct Node {
 }
 
 impl FromStr for Node {
-	type Err = Error;
+	type Err = UtilError;
 	fn from_str(s: &str) -> Result<Self, Self::Err> {
 		let (id, endpoint) = if &s[0..8] == "enode://" && s.len() > 136 && &s[136..137] == "@" {
 			(try!(NodeId::from_str(&s[8..136])), try!(NodeEndpoint::from_str(&s[137..])))
@@ -189,7 +190,7 @@ impl<'s> HostIo<'s> {
 	}
 
 	/// Send a packet over the network to another peer.
-	pub fn send(&mut self, peer: PeerId, packet_id: PacketId, data: Vec<u8>) -> Result<(), Error> {
+	pub fn send(&mut self, peer: PeerId, packet_id: PacketId, data: Vec<u8>) -> Result<(), UtilError> {
 		match self.connections.get_mut(Token(peer)) {
 			Some(&mut ConnectionEntry::Session(ref mut s)) => {
 				s.send_packet(self.protocol, packet_id as u8, &data).unwrap_or_else(|e| {
@@ -204,7 +205,7 @@ impl<'s> HostIo<'s> {
 	}
 
 	/// Respond to a current network message. Panics if no there is no packet in the context.
-	pub fn respond(&mut self, packet_id: PacketId, data: Vec<u8>) -> Result<(), Error> {
+	pub fn respond(&mut self, packet_id: PacketId, data: Vec<u8>) -> Result<(), UtilError> {
 		match self.session {
 			Some(session) => self.send(session.as_usize(), packet_id, data),
 			None => {
@@ -214,7 +215,7 @@ impl<'s> HostIo<'s> {
 	}
 
 	/// Register a new IO timer. Returns a new timer toke. 'ProtocolHandler::timeout' will be called with the token.
-	pub fn register_timer(&mut self, ms: u64) -> Result<TimerToken, Error>{
+	pub fn register_timer(&mut self, ms: u64) -> Result<TimerToken, UtilError>{
 		match self.timers.insert(UserTimer {
 			delay: ms,
 			protocol: self.protocol,
@@ -292,7 +293,7 @@ pub struct Host {
 }
 
 impl Host {
-	pub fn start(event_loop: &mut EventLoop<Host>) -> Result<(), Error> {
+	pub fn start(event_loop: &mut EventLoop<Host>) -> Result<(), UtilError> {
 		let config = NetworkConfiguration::new();
 		/*
 		   match ::ifaces::Interface::get_all().unwrap().into_iter().filter(|x| x.kind == ::ifaces::Kind::Packet && x.addr.is_some()).next() {
diff --git a/src/network/mod.rs b/src/network/mod.rs
index df0da2c13..cdce08d00 100644
--- a/src/network/mod.rs
+++ b/src/network/mod.rs
@@ -69,49 +69,23 @@ pub enum DisconnectReason
 }
 
 #[derive(Debug)]
-pub enum Error {
-	Crypto(::crypto::CryptoError),
-	Io(::std::io::Error),
+pub enum NetworkError {
 	Auth,
 	BadProtocol,
-	AddressParse(::std::net::AddrParseError),
-	AddressResolve(Option<::std::io::Error>),
-	NodeIdParse(::error::EthcoreError),
 	PeerNotFound,
-	Disconnect(DisconnectReason)
+	Disconnect(DisconnectReason),
+	Mio(::std::io::Error),
 }
 
-impl From<::std::io::Error> for Error {
-	fn from(err: ::std::io::Error) -> Error {
-		Error::Io(err)
+impl From<::rlp::DecoderError> for NetworkError {
+	fn from(_err: ::rlp::DecoderError) -> NetworkError {
+		NetworkError::Auth
 	}
 }
 
-impl From<::crypto::CryptoError> for Error {
-	fn from(err: ::crypto::CryptoError) -> Error {
-		Error::Crypto(err)
-	}
-}
-
-impl From<::std::net::AddrParseError> for Error {
-	fn from(err: ::std::net::AddrParseError) -> Error {
-		Error::AddressParse(err)
-	}
-}
-impl From<::error::EthcoreError> for Error {
-	fn from(err: ::error::EthcoreError) -> Error {
-		Error::NodeIdParse(err)
-	}
-}
-impl From<::rlp::DecoderError> for Error {
-	fn from(_err: ::rlp::DecoderError) -> Error {
-		Error::Auth
-	}
-}
-
-impl From<::mio::NotifyError<host::HostMessage>> for Error {
-	fn from(_err: ::mio::NotifyError<host::HostMessage>) -> Error {
-		Error::Io(::std::io::Error::new(::std::io::ErrorKind::ConnectionAborted, "Network IO notification error"))
+impl From<::mio::NotifyError<host::HostMessage>> for NetworkError {
+	fn from(_err: ::mio::NotifyError<host::HostMessage>) -> NetworkError {
+		NetworkError::Mio(::std::io::Error::new(::std::io::ErrorKind::ConnectionAborted, "Network IO notification error"))
 	}
 }
 
diff --git a/src/network/service.rs b/src/network/service.rs
index 7598ffdd6..23cbb57d9 100644
--- a/src/network/service.rs
+++ b/src/network/service.rs
@@ -1,6 +1,7 @@
 use std::thread::{self, JoinHandle};
 use mio::*;
-use network::{Error, ProtocolHandler};
+use error::*;
+use network::{NetworkError, ProtocolHandler};
 use network::host::{Host, HostMessage, PeerId, PacketId, ProtocolId};
 
 /// IO Service with networking
@@ -11,7 +12,7 @@ pub struct NetworkService {
 
 impl NetworkService {
 	/// Starts IO event loop
-	pub fn start() -> Result<NetworkService, Error> {
+	pub fn start() -> Result<NetworkService, UtilError> {
 		let mut event_loop = EventLoop::new().unwrap();
         let channel = event_loop.channel();
 		let thread = thread::spawn(move || {
@@ -24,7 +25,7 @@ impl NetworkService {
 	}
 
 	/// Send a message over the network. Normaly `HostIo::send` should be used. This can be used from non-io threads.
-	pub fn send(&mut self, peer: &PeerId, packet_id: PacketId, protocol: ProtocolId, data: &[u8]) -> Result<(), Error> {
+	pub fn send(&mut self, peer: &PeerId, packet_id: PacketId, protocol: ProtocolId, data: &[u8]) -> Result<(), NetworkError> {
 		try!(self.host_channel.send(HostMessage::Send {
 			peer: *peer,
 			packet_id: packet_id,
@@ -35,7 +36,7 @@ impl NetworkService {
 	}
 
 	/// Regiter a new protocol handler with the event loop.
-	pub fn register_protocol(&mut self, handler: Box<ProtocolHandler+Send>, protocol: ProtocolId, versions: &[u8]) -> Result<(), Error> {
+	pub fn register_protocol(&mut self, handler: Box<ProtocolHandler+Send>, protocol: ProtocolId, versions: &[u8]) -> Result<(), NetworkError> {
 		try!(self.host_channel.send(HostMessage::AddHandler {
 			handler: handler,
 			protocol: protocol,
diff --git a/src/network/session.rs b/src/network/session.rs
index 720902150..d37ec086f 100644
--- a/src/network/session.rs
+++ b/src/network/session.rs
@@ -3,7 +3,8 @@ use hash::*;
 use rlp::*;
 use network::connection::{EncryptedConnection, Packet};
 use network::handshake::Handshake;
-use network::{Error, DisconnectReason};
+use error::*;
+use network::{NetworkError, DisconnectReason};
 use network::host::*;
 
 pub struct Session {
@@ -64,7 +65,7 @@ const PACKET_USER: u8 = 0x10;
 const PACKET_LAST: u8 = 0x7f;
 
 impl Session {
-	pub fn new(h: Handshake, event_loop: &mut EventLoop<Host>, host: &HostInfo) -> Result<Session, Error> {
+	pub fn new(h: Handshake, event_loop: &mut EventLoop<Host>, host: &HostInfo) -> Result<Session, UtilError> {
 		let id = h.id.clone();
 		let connection = try!(EncryptedConnection::new(h));
 		let mut session = Session {
@@ -83,14 +84,14 @@ impl Session {
 		Ok(session)
 	}
 
-	pub fn readable(&mut self, event_loop: &mut EventLoop<Host>, host: &HostInfo) -> Result<SessionData, Error> {
+	pub fn readable(&mut self, event_loop: &mut EventLoop<Host>, host: &HostInfo) -> Result<SessionData, UtilError> {
 		match try!(self.connection.readable(event_loop)) {
-			Some(data)  => self.read_packet(data, host),
+			Some(data) => Ok(try!(self.read_packet(data, host))),
 			None => Ok(SessionData::None)
 		}
 	}
 
-	pub fn writable(&mut self, event_loop: &mut EventLoop<Host>, _host: &HostInfo) -> Result<(), Error> {
+	pub fn writable(&mut self, event_loop: &mut EventLoop<Host>, _host: &HostInfo) -> Result<(), UtilError> {
 		self.connection.writable(event_loop)
 	}
 
@@ -98,7 +99,7 @@ impl Session {
 		self.info.capabilities.iter().any(|c| c.protocol == protocol)
 	}
 
-	pub fn send_packet(&mut self, protocol: &str, packet_id: u8, data: &[u8]) -> Result<(), Error> {
+	pub fn send_packet(&mut self, protocol: &str, packet_id: u8, data: &[u8]) -> Result<(), UtilError> {
 		let mut i = 0usize;
 		while protocol != self.info.capabilities[i].protocol {
 			i += 1;
@@ -114,13 +115,13 @@ impl Session {
 		self.connection.send_packet(&rlp.out())
 	}
 
-	fn read_packet(&mut self, packet: Packet, host: &HostInfo) -> Result<SessionData, Error> {
+	fn read_packet(&mut self, packet: Packet, host: &HostInfo) -> Result<SessionData, UtilError> {
 		if packet.data.len() < 2 {
-			return Err(Error::BadProtocol);
+			return Err(From::from(NetworkError::BadProtocol));
 		}
 		let packet_id = packet.data[0];
 		if packet_id != PACKET_HELLO && packet_id != PACKET_DISCONNECT && !self.had_hello {
-			return Err(Error::BadProtocol);
+			return Err(From::from(NetworkError::BadProtocol));
 		}
 		match packet_id {
 			PACKET_HELLO => {
@@ -128,7 +129,7 @@ impl Session {
 				try!(self.read_hello(&rlp, host));
 				Ok(SessionData::Ready)
 			},
-			PACKET_DISCONNECT => Err(Error::Disconnect(DisconnectReason::DisconnectRequested)),
+			PACKET_DISCONNECT => Err(From::from(NetworkError::Disconnect(DisconnectReason::DisconnectRequested))),
 			PACKET_PING => {
 				try!(self.write_pong());
 				Ok(SessionData::None)
@@ -157,7 +158,7 @@ impl Session {
 		}
 	}
 
-	fn write_hello(&mut self, host: &HostInfo) -> Result<(), Error>  {
+	fn write_hello(&mut self, host: &HostInfo) -> Result<(), UtilError> {
 		let mut rlp = RlpStream::new();
 		rlp.append(&(PACKET_HELLO as u32));
 		rlp.append_list(5)
@@ -169,7 +170,7 @@ impl Session {
 		self.connection.send_packet(&rlp.out())
 	}
 
-	fn read_hello(&mut self, rlp: &UntrustedRlp, host: &HostInfo) -> Result<(), Error> {
+	fn read_hello(&mut self, rlp: &UntrustedRlp, host: &HostInfo) -> Result<(), UtilError> {
 		let protocol = try!(rlp.val_at::<u32>(0));
 		let client_version = try!(rlp.val_at::<String>(1));
 		let peer_caps = try!(rlp.val_at::<Vec<PeerCapabilityInfo>>(2));
@@ -210,37 +211,37 @@ impl Session {
 		trace!(target: "net", "Hello: {} v{} {} {:?}", client_version, protocol, id, caps);
 		self.info.capabilities = caps;
 		if protocol != host.protocol_version {
-			return Err(self.disconnect(DisconnectReason::UselessPeer));
+			return Err(From::from(self.disconnect(DisconnectReason::UselessPeer)));
 		}
 		self.had_hello = true;
 		Ok(())
 	}
 
-	fn write_ping(&mut self) -> Result<(), Error>  {
+	fn write_ping(&mut self) -> Result<(), UtilError> {
 		self.send(try!(Session::prepare(PACKET_PING, 0)))
 	}
 
-	fn write_pong(&mut self) -> Result<(), Error>  {
+	fn write_pong(&mut self) -> Result<(), UtilError> {
 		self.send(try!(Session::prepare(PACKET_PONG, 0)))
 	}
 
-	fn disconnect(&mut self, reason: DisconnectReason) -> Error {
+	fn disconnect(&mut self, reason: DisconnectReason) -> NetworkError {
 		let mut rlp = RlpStream::new();
 		rlp.append(&(PACKET_DISCONNECT as u32));
 		rlp.append_list(1);
 		rlp.append(&(reason.clone() as u32));
 		self.connection.send_packet(&rlp.out()).ok();
-		Error::Disconnect(reason)
+		NetworkError::Disconnect(reason)
 	}
 
-	fn prepare(packet_id: u8, items: usize) -> Result<RlpStream, Error> {
+	fn prepare(packet_id: u8, items: usize) -> Result<RlpStream, UtilError> {
 		let mut rlp = RlpStream::new_list(1);
 		rlp.append(&(packet_id as u32));
 		rlp.append_list(items);
 		Ok(rlp)
 	}
 
-	fn send(&mut self, rlp: RlpStream) -> Result<(), Error> {
+	fn send(&mut self, rlp: RlpStream) -> Result<(), UtilError> {
 		self.connection.send_packet(&rlp.out())
 	}
 }
diff --git a/src/overlaydb.rs b/src/overlaydb.rs
index b5bbf4299..5539a8893 100644
--- a/src/overlaydb.rs
+++ b/src/overlaydb.rs
@@ -66,7 +66,7 @@ impl OverlayDB {
 	///   assert!(m.exists(&key));				// key now still exists.
 	/// }
 	/// ```
-	pub fn commit(&mut self) -> Result<u32, EthcoreError> {
+	pub fn commit(&mut self) -> Result<u32, UtilError> {
 		let mut ret = 0u32;
 		for i in self.overlay.drain().into_iter() {
 			let (key, (value, rc)) = i;