diff --git a/ethcore/src/engine.rs b/ethcore/src/engine.rs
index 344144c6e..050d5b499 100644
--- a/ethcore/src/engine.rs
+++ b/ethcore/src/engine.rs
@@ -14,6 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
+//! Consensus engine specification
+
 use common::*;
 use util::keys::store::AccountProvider;
 use block::ExecutedBlock;
diff --git a/ethcore/src/lib.rs b/ethcore/src/lib.rs
index 0b62ec4fb..346711327 100644
--- a/ethcore/src/lib.rs
+++ b/ethcore/src/lib.rs
@@ -103,6 +103,7 @@ pub mod trace;
 pub mod spec;
 pub mod views;
 pub mod pod_state;
+pub mod engine;
 
 mod db;
 mod common;
@@ -112,7 +113,6 @@ mod env_info;
 mod pod_account;
 mod account_diff;
 mod state_diff;
-mod engine;
 mod state;
 mod account;
 mod account_db;
diff --git a/miner/src/miner.rs b/miner/src/miner.rs
index 33d21613f..e89fe2bf8 100644
--- a/miner/src/miner.rs
+++ b/miner/src/miner.rs
@@ -25,6 +25,8 @@ use ethcore::block::{ClosedBlock, IsBlock};
 use ethcore::error::*;
 use ethcore::client::{Executive, Executed, EnvInfo, TransactOptions};
 use ethcore::transaction::SignedTransaction;
+use ethcore::spec::Spec;
+use ethcore::engine::Engine;
 use super::{MinerService, MinerStatus, TransactionQueue, AccountDetails, TransactionImportResult, TransactionOrigin};
 
 /// Keeps track of transactions using priority queue and holds currently mined block.
@@ -39,6 +41,7 @@ pub struct Miner {
 	gas_floor_target: RwLock<U256>,
 	author: RwLock<Address>,
 	extra_data: RwLock<Bytes>,
+	spec: Spec,
 
 	accounts: RwLock<Option<Arc<AccountService>>>,		// TODO: this is horrible since AccountService already contains a single RwLock field. refactor.
 }
@@ -55,13 +58,14 @@ impl Default for Miner {
 			author: RwLock::new(Address::default()),
 			extra_data: RwLock::new(Vec::new()),
 			accounts: RwLock::new(None),
+			spec: Spec::new_test(),
 		}
 	}
 }
 
 impl Miner {
 	/// Creates new instance of miner
-	pub fn new(force_sealing: bool) -> Arc<Miner> {
+	pub fn new(force_sealing: bool, spec: Spec) -> Arc<Miner> {
 		Arc::new(Miner {
 			transaction_queue: Mutex::new(TransactionQueue::new()),
 			force_sealing: force_sealing,
@@ -72,11 +76,12 @@ impl Miner {
 			author: RwLock::new(Address::default()),
 			extra_data: RwLock::new(Vec::new()),
 			accounts: RwLock::new(None),
+			spec: spec,
 		})
 	}
 
 	/// Creates new instance of miner
-	pub fn with_accounts(force_sealing: bool, accounts: Arc<AccountService>) -> Arc<Miner> {
+	pub fn with_accounts(force_sealing: bool, spec: Spec, accounts: Arc<AccountService>) -> Arc<Miner> {
 		Arc::new(Miner {
 			transaction_queue: Mutex::new(TransactionQueue::new()),
 			force_sealing: force_sealing,
@@ -87,9 +92,14 @@ impl Miner {
 			author: RwLock::new(Address::default()),
 			extra_data: RwLock::new(Vec::new()),
 			accounts: RwLock::new(Some(accounts)),
+			spec: spec,
 		})
 	}
 
+	fn engine(&self) -> &Engine {
+		self.spec.engine.deref()
+	}
+
 	/// Prepares new block for sealing including top transactions from queue.
 	#[cfg_attr(feature="dev", allow(match_same_arms))]
 	fn prepare_sealing(&self, chain: &BlockChainClient) {
@@ -166,7 +176,7 @@ impl Miner {
 				trace!(target: "miner", "prepare_sealing: block has transaction - attempting internal seal.");
 				// block with transactions - see if we can seal immediately.
 				let a = self.accounts.read().unwrap();
-				let s = chain.generate_seal(block.block(), match *a.deref() {
+				let s = self.engine().generate_seal(block.block(), match *a.deref() {
 					Some(ref x) => Some(x.deref() as &AccountProvider),
 					None => None,
 				});
diff --git a/parity/main.rs b/parity/main.rs
index dd70d39cc..4896e42cf 100644
--- a/parity/main.rs
+++ b/parity/main.rs
@@ -145,7 +145,7 @@ fn execute_client(conf: Configuration) {
 	let client = service.client();
 
 	// Miner
-	let miner = Miner::with_accounts(conf.args.flag_force_sealing, account_service.clone());
+	let miner = Miner::with_accounts(conf.args.flag_force_sealing, conf.spec(), account_service.clone());
 	miner.set_author(conf.author());
 	miner.set_gas_floor_target(conf.gas_floor_target());
 	miner.set_extra_data(conf.extra_data());