diff --git a/network/src/validation.rs b/network/src/validation.rs
index 69891913b489..8914b417fa54 100644
--- a/network/src/validation.rs
+++ b/network/src/validation.rs
@@ -330,6 +330,7 @@ impl<P, E, N, T> ParachainNetwork for ValidationNetwork<P, E, N, T> where
 		&self,
 		table: Arc<SharedTable>,
 		authorities: &[ValidatorId],
+		exit: exit_future::Exit,
 	) -> Self::BuildTableRouter {
 		let parent_hash = *table.consensus_parent_hash();
 		let local_session_key = table.session_key();
@@ -354,7 +355,7 @@ impl<P, E, N, T> ParachainNetwork for ValidationNetwork<P, E, N, T> where
 				let table_router_clone = table_router.clone();
 				let work = table_router.checked_statements()
 					.for_each(move |msg| { table_router_clone.import_statement(msg); Ok(()) });
-				executor.spawn(work);
+				executor.spawn(work.select(exit).map(|_| ()).map_err(|_| ()));
 
 				table_router
 			});
diff --git a/runtime/src/parachains.rs b/runtime/src/parachains.rs
index 9f8378797c08..8f450a3a351a 100644
--- a/runtime/src/parachains.rs
+++ b/runtime/src/parachains.rs
@@ -22,9 +22,7 @@ use parity_codec::{Decode, HasCompact};
 use srml_support::{decl_storage, decl_module, fail, ensure};
 
 use bitvec::{bitvec, BigEndian};
-use sr_primitives::traits::{
-	Hash as HashT, BlakeTwo256, Member, CheckedConversion, Saturating, One, Zero,
-};
+use sr_primitives::traits::{Hash as HashT, BlakeTwo256, Member, CheckedConversion, Saturating, One};
 use primitives::{Hash, Balance, parachain::{
 	self, Id as ParaId, Chain, DutyRoster, AttestedCandidate, Statement, AccountIdConversion,
 	ParachainDispatchOrigin, UpwardMessage, BlockIngressRoots,
@@ -243,9 +241,11 @@ decl_storage! {
 		config(parachains): Vec<(ParaId, Vec<u8>, Vec<u8>)>;
 		config(_phdata): PhantomData<T>;
 		build(|storage: &mut StorageOverlay, _: &mut ChildrenStorageOverlay, config: &GenesisConfig<T>| {
+			use sr_primitives::traits::Zero;
+
 			let mut p = config.parachains.clone();
-			p.sort_unstable_by_key(|&(ref id, _, _)| id.clone());
-			p.dedup_by_key(|&mut (ref id, _, _)| id.clone());
+			p.sort_unstable_by_key(|&(ref id, _, _)| *id);
+			p.dedup_by_key(|&mut (ref id, _, _)| *id);
 
 			let only_ids: Vec<_> = p.iter().map(|&(ref id, _, _)| id).cloned().collect();
 
diff --git a/validation/src/lib.rs b/validation/src/lib.rs
index bd946f4bbe2c..652d98f64502 100644
--- a/validation/src/lib.rs
+++ b/validation/src/lib.rs
@@ -147,6 +147,7 @@ pub trait Network {
 		&self,
 		table: Arc<SharedTable>,
 		authorities: &[SessionKey],
+		exit: exit_future::Exit,
 	) -> Self::BuildTableRouter;
 }
 
@@ -313,11 +314,14 @@ impl<C, N, P> ParachainValidation<C, N, P> where
 		let (group_info, local_duty) = make_group_info(
 			duty_roster,
 			&authorities,
-			sign_with.public().into(),
+			sign_with.public(),
 		)?;
 
-		info!("Starting parachain attestation session on top of parent {:?}. Local parachain duty is {:?}",
-			parent_hash, local_duty.validation);
+		info!(
+			"Starting parachain attestation session on top of parent {:?}. Local parachain duty is {:?}",
+			parent_hash,
+			local_duty.validation,
+		);
 
 		let active_parachains = self.client.runtime_api().active_parachains(&id)?;
 
@@ -331,25 +335,23 @@ impl<C, N, P> ParachainValidation<C, N, P> where
 			self.extrinsic_store.clone(),
 			max_block_data_size,
 		));
+
+		let (_drop_signal, exit) = exit_future::signal();
+
 		let router = self.network.communication_for(
 			table.clone(),
 			&authorities,
+			exit.clone(),
 		);
 
-		let drop_signal = match local_duty.validation {
-			Chain::Parachain(id) => Some(self.launch_work(
-				parent_hash,
-				id,
-				router,
-				max_block_data_size,
-			)),
-			Chain::Relay => None,
-		};
+		if let Chain::Parachain(id) = local_duty.validation {
+			self.launch_work(parent_hash, id, router, max_block_data_size, exit);
+		}
 
 		let tracker = Arc::new(AttestationTracker {
 			table,
 			started: Instant::now(),
-			_drop_signal: drop_signal
+			_drop_signal,
 		});
 
 		live_instances.insert(parent_hash, tracker.clone());
@@ -369,10 +371,10 @@ impl<C, N, P> ParachainValidation<C, N, P> where
 		validation_para: ParaId,
 		build_router: N::BuildTableRouter,
 		max_block_data_size: Option<u64>,
-	) -> exit_future::Signal {
+		exit: exit_future::Exit,
+	) {
 		use extrinsic_store::Data;
 
-		let (signal, exit) = exit_future::signal();
 		let (collators, client) = (self.collators.clone(), self.client.clone());
 		let extrinsic_store = self.extrinsic_store.clone();
 
@@ -428,16 +430,15 @@ impl<C, N, P> ParachainValidation<C, N, P> where
 			.then(|_| Ok(()));
 
 		// spawn onto thread pool.
-		if let Err(_) = self.handle.execute(Box::new(cancellable_work)) {
+		if self.handle.execute(Box::new(cancellable_work)).is_err() {
 			error!("Failed to spawn cancellable work task");
 		}
-		signal
 	}
 }
 
 /// Parachain validation for a single block.
 struct AttestationTracker {
-	_drop_signal: Option<exit_future::Signal>,
+	_drop_signal: exit_future::Signal,
 	table: Arc<SharedTable>,
 	started: Instant,
 }
@@ -544,7 +545,7 @@ impl<C, N, P, SC, TxApi> consensus::Environment<Block> for ProposerFactory<C, N,
 			parent_id,
 			parent_number: parent_header.number,
 			transaction_pool: self.transaction_pool.clone(),
-			slot_duration: self.aura_slot_duration.clone(),
+			slot_duration: self.aura_slot_duration,
 		})
 	}
 }