diff --git a/Cargo.lock b/Cargo.lock
index 8810fc7ebb98f..82952d8a5e803 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3885,6 +3885,7 @@ dependencies = [
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
+ "srml-authorship 0.1.0",
  "srml-session 2.0.0",
  "srml-support 2.0.0",
  "srml-system 2.0.0",
diff --git a/core/sr-primitives/src/traits.rs b/core/sr-primitives/src/traits.rs
index f7d55dda79a12..6e1b8286314c6 100644
--- a/core/sr-primitives/src/traits.rs
+++ b/core/sr-primitives/src/traits.rs
@@ -602,6 +602,24 @@ pub trait IsMember<MemberId> {
 	fn is_member(member_id: &MemberId) -> bool;
 }
 
+/// Mean for getting the current session keys.
+pub trait CurrentSessionKeys<AccountId> {
+	/// Get the keys of the current session.
+	fn current_keys<Key: Decode + Default + TypedKey>() -> Vec<(AccountId, Key)>;
+}
+
+impl<T> CurrentSessionKeys<T> for () {
+	fn current_keys<Key>() -> Vec<(T, Key)> {
+		Vec::new()
+	}
+}
+
+/// Disable a validator referenced by an `AccountId`.
+pub trait DisableValidator<AccountId> {
+	/// Disable a validator referenced by an `AccountId`.
+	fn disable(account_id: &AccountId) -> Result<(), ()>;
+}
+
 /// Something which fulfills the abstract idea of a Substrate header. It has types for a `Number`,
 /// a `Hash` and a `Digest`. It provides access to an `extrinsics_root`, `state_root` and
 /// `parent_hash`, as well as a `digest` and a block `number`.
diff --git a/core/test-runtime/src/lib.rs b/core/test-runtime/src/lib.rs
index 98d2437059659..da6e6032393e4 100644
--- a/core/test-runtime/src/lib.rs
+++ b/core/test-runtime/src/lib.rs
@@ -368,6 +368,7 @@ parameter_types! {
 
 impl srml_babe::Trait for Runtime {
 	type EpochDuration = EpochDuration;
+	type CurrentSessionKeys = ();
 	type ExpectedBlockTime = ExpectedBlockTime;
 }
 
diff --git a/node/cli/src/chain_spec.rs b/node/cli/src/chain_spec.rs
index 6372146a45ecd..b2e20420ada6b 100644
--- a/node/cli/src/chain_spec.rs
+++ b/node/cli/src/chain_spec.rs
@@ -21,8 +21,8 @@ use primitives::{ed25519, sr25519, Pair, crypto::UncheckedInto};
 use node_primitives::{AccountId, Balance};
 use node_runtime::{
 	BabeConfig,	BalancesConfig, ContractsConfig, CouncilConfig, DemocracyConfig,
-	ElectionsConfig, GrandpaConfig, ImOnlineConfig, IndicesConfig, Perbill,
-	SessionConfig,	SessionKeys, StakerStatus, StakingConfig, SudoConfig, SystemConfig,
+	ElectionsConfig, GrandpaConfig, IndicesConfig, Perbill, SessionConfig,
+	SessionKeys, StakerStatus, StakingConfig, SudoConfig, SystemConfig,
 	TechnicalCommitteeConfig, WASM_BINARY,
 };
 use node_runtime::constants::{time::*, currency::*};
@@ -161,10 +161,6 @@ fn staging_testnet_config_genesis() -> GenesisConfig {
 		babe: Some(BabeConfig {
 			authorities: initial_authorities.iter().map(|x| (x.2.clone(), 1)).collect(),
 		}),
-		im_online: Some(ImOnlineConfig {
-			gossip_at: 0,
-			last_new_era_start: 0,
-		}),
 		grandpa: Some(GrandpaConfig {
 			authorities: initial_authorities.iter().map(|x| (x.3.clone(), 1)).collect(),
 		}),
@@ -304,10 +300,6 @@ pub fn testnet_genesis(
 		babe: Some(BabeConfig {
 			authorities: initial_authorities.iter().map(|x| (x.2.clone(), 1)).collect(),
 		}),
-		im_online: Some(ImOnlineConfig{
-			gossip_at: 0,
-			last_new_era_start: 0,
-		}),
 		grandpa: Some(GrandpaConfig {
 			authorities: initial_authorities.iter().map(|x| (x.3.clone(), 1)).collect(),
 		}),
diff --git a/node/executor/src/lib.rs b/node/executor/src/lib.rs
index 572d0ca1499bc..83fd65a0317c2 100644
--- a/node/executor/src/lib.rs
+++ b/node/executor/src/lib.rs
@@ -388,7 +388,6 @@ mod tests {
 				gas_price: 1 * MILLICENTS,
 			}),
 			sudo: Some(Default::default()),
-			im_online: Some(Default::default()),
 			grandpa: Some(GrandpaConfig {
 				authorities: vec![],
 			}),
diff --git a/node/runtime/src/lib.rs b/node/runtime/src/lib.rs
index 06285571ba8b2..f75cde04a6b85 100644
--- a/node/runtime/src/lib.rs
+++ b/node/runtime/src/lib.rs
@@ -79,8 +79,8 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	// and set impl_version to equal spec_version. If only runtime
 	// implementation changes and behavior does not, then leave spec_version as
 	// is and increment impl_version.
-	spec_version: 129,
-	impl_version: 129,
+	spec_version: 130,
+	impl_version: 130,
 	apis: RUNTIME_API_VERSIONS,
 };
 
@@ -134,6 +134,7 @@ parameter_types! {
 impl babe::Trait for Runtime {
 	type EpochDuration = EpochDuration;
 	type ExpectedBlockTime = ExpectedBlockTime;
+	type CurrentSessionKeys = session::CurrentSessionKeys<Self>;
 }
 
 impl indices::Trait for Runtime {
@@ -184,7 +185,7 @@ impl authorship::Trait for Runtime {
 	type FindAuthor = session::FindAccountFromAuthorIndex<Self, Babe>;
 	type UncleGenerations = UncleGenerations;
 	type FilterUncle = ();
-	type EventHandler = Staking;
+	type EventHandler = (ImOnline, Staking);
 }
 
 type SessionHandlers = (Grandpa, Babe, ImOnline);
@@ -212,6 +213,7 @@ impl session::Trait for Runtime {
 	type Keys = SessionKeys;
 	type ValidatorId = AccountId;
 	type ValidatorIdOf = staking::StashOf<Self>;
+	type AccountIdOf = staking::ControllerOf<Self>;
 	type SelectInitialValidators = Staking;
 }
 
@@ -375,6 +377,8 @@ impl im_online::Trait for Runtime {
 	type SessionsPerEra = SessionsPerEra;
 	type UncheckedExtrinsic = UncheckedExtrinsic;
 	type IsValidAuthorityId = Babe;
+	type AuthorityIdOf = babe::AuthorityIdOf<Self, BabeId>;
+	type DisableValidator = staking::DisableValidatorInterface<Self>;
 }
 
 impl grandpa::Trait for Runtime {
@@ -415,7 +419,7 @@ construct_runtime!(
 		Treasury: treasury::{Module, Call, Storage, Event<T>},
 		Contracts: contracts,
 		Sudo: sudo,
-		ImOnline: im_online::{default, ValidateUnsigned},
+		ImOnline: im_online::{Module, Call, Event<T>, ValidateUnsigned},
 	}
 );
 
diff --git a/srml/babe/src/lib.rs b/srml/babe/src/lib.rs
index 8e72fdffd4fbf..3358a69c90914 100644
--- a/srml/babe/src/lib.rs
+++ b/srml/babe/src/lib.rs
@@ -25,7 +25,10 @@ use rstd::{result, prelude::*};
 use srml_support::{decl_storage, decl_module, StorageValue, StorageMap, traits::FindAuthor, traits::Get};
 use timestamp::{OnTimestampSet};
 use sr_primitives::{generic::DigestItem, ConsensusEngineId};
-use sr_primitives::traits::{IsMember, SaturatedConversion, Saturating, RandomnessBeacon, Convert};
+use sr_primitives::traits::{
+	CurrentSessionKeys, IsMember, SaturatedConversion, Saturating, RandomnessBeacon, Convert,
+	TypedKey,
+};
 #[cfg(feature = "std")]
 use timestamp::TimestampInherentData;
 use parity_codec::{Encode, Decode};
@@ -109,7 +112,11 @@ impl ProvideInherentData for InherentDataProvider {
 
 pub trait Trait: timestamp::Trait {
 	type EpochDuration: Get<u64>;
+
 	type ExpectedBlockTime: Get<Self::Moment>;
+
+	/// Retrieve the current session keys.
+	type CurrentSessionKeys: CurrentSessionKeys<Self::AccountId>;
 }
 
 /// The length of the BABE randomness
@@ -234,6 +241,27 @@ impl<T: Trait> IsMember<AuthorityId> for Module<T> {
 	}
 }
 
+/// A `Convert` implementation that finds the babe authority id of the given controller
+/// account, if any.
+pub struct AuthorityIdOf<T, Id>(rstd::marker::PhantomData<T>, rstd::marker::PhantomData<Id>);
+
+impl<T, AuthorityId> Convert<T::AccountId, Option<AuthorityId>> for AuthorityIdOf<T, AuthorityId>
+	where
+		T: Trait,
+		AuthorityId: Decode + Default + TypedKey,
+{
+	fn convert(account_id: T::AccountId) -> Option<AuthorityId> {
+		let keys = T::CurrentSessionKeys::current_keys::<AuthorityId>();
+		let maybe_authority_id = keys
+			.into_iter()
+			.find(|(id, _)| {
+				*id == account_id
+			})
+			.map(|(_, a)| a);
+		maybe_authority_id
+	}
+}
+
 impl<T: Trait> session::ShouldEndSession<T::BlockNumber> for Module<T> {
 	fn should_end_session(_: T::BlockNumber) -> bool {
 		let diff = CurrentSlot::get().saturating_sub(EpochStartSlot::get());
diff --git a/srml/im-online/Cargo.toml b/srml/im-online/Cargo.toml
index c015e5e4c51a8..594be69df2d8a 100644
--- a/srml/im-online/Cargo.toml
+++ b/srml/im-online/Cargo.toml
@@ -5,6 +5,7 @@ authors = ["Parity Technologies <admin@parity.io>"]
 edition = "2018"
 
 [dependencies]
+authorship = { package = "srml-authorship", path = "../authorship", default-features = false }
 parity-codec = { version = "4.1.1", default-features = false, features = ["derive"] }
 sr-primitives = { path = "../../core/sr-primitives", default-features = false }
 primitives = { package = "substrate-primitives",  path = "../../core/primitives", default-features = false }
diff --git a/srml/im-online/src/lib.rs b/srml/im-online/src/lib.rs
index 8254cb60780fd..a2ecd01328015 100644
--- a/srml/im-online/src/lib.rs
+++ b/srml/im-online/src/lib.rs
@@ -63,7 +63,9 @@
 //!
 //! ## Dependencies
 //!
-//! This module depends on the [Session module](../srml_session/index.html).
+//! This module depends on the [Session module](../srml_session/index.html) for
+//! generic session functionality and on the [Authorship module](../srml_authorship/index.html)
+//! to mark validators automatically as online once they author a block.
 
 // Ensure we're `no_std` when compiling for Wasm.
 #![cfg_attr(not(feature = "std"), no_std)]
@@ -76,7 +78,9 @@ use primitives::{
 };
 use parity_codec::{Encode, Decode};
 use sr_primitives::{
-	ApplyError, traits::{Member, IsMember, Extrinsic as ExtrinsicT},
+	ApplyError, traits::{
+		Convert, DisableValidator, Member, IsMember, Extrinsic as ExtrinsicT, Zero,
+	},
 	transaction_validity::{TransactionValidity, TransactionLongevity, ValidTransaction},
 };
 use rstd::prelude::*;
@@ -158,6 +162,12 @@ pub trait Trait: system::Trait + session::Trait {
 
 	/// Determine if an `AuthorityId` is a valid authority.
 	type IsValidAuthorityId: IsMember<Self::AuthorityId>;
+
+	/// A conversion of `AccountId` to `AuthorityId`.
+	type AuthorityIdOf: Convert<Self::AccountId, Option<Self::AuthorityId>>;
+
+	/// Disable a given validator.
+	type DisableValidator: DisableValidator<Self::AccountId>;
 }
 
 decl_event!(
@@ -173,15 +183,24 @@ decl_event!(
 decl_storage! {
 	trait Store for Module<T: Trait> as ImOnline {
 		// The block number when we should gossip.
-		GossipAt get(gossip_at) config(): T::BlockNumber;
+		GossipAt get(gossip_at) build(|_| T::BlockNumber::zero()): T::BlockNumber;
 
 		// The session index when the last new era started.
-		LastNewEraStart get(last_new_era_start) config(): Option<session::SessionIndex>;
+		LastNewEraStart get(last_new_era_start): Option<session::SessionIndex>;
 
 		// For each session index we keep a mapping of `AuthorityId` to
 		// `offchain::OpaqueNetworkState`.
 		ReceivedHeartbeats get(received_heartbeats): double_map session::SessionIndex,
 			blake2_256(T::AuthorityId) => Vec<u8>;
+
+		// For each session index we track if an `AuthorityId` was noted as
+		// a block author by the authorship module.
+		BlockAuthors get(block_authors): double_map session::SessionIndex,
+			blake2_256(T::AuthorityId) => bool;
+
+		// The validators in the current session.
+		CurrentSessionValidators get(current_session_validators):
+			Vec<(T::AccountId, T::AuthorityId)>;
 	}
 }
 
@@ -336,25 +355,61 @@ impl<T: Trait> Module<T> {
 			Some(start) => {
 				// iterate over every session
 				for index in start..curr  {
-					if <ReceivedHeartbeats<T>>::exists(&index, authority_id) {
+					let got_heartbeat = <ReceivedHeartbeats<T>>::exists(&index, authority_id);
+					let was_author = <BlockAuthors<T>>::exists(&index, authority_id);
+					if got_heartbeat || was_author {
 						return true;
 					}
 				}
 				false
 			},
-			None => <ReceivedHeartbeats<T>>::exists(&curr, authority_id),
+			None => {
+				let got_heartbeat = <ReceivedHeartbeats<T>>::exists(&curr, authority_id);
+				let was_author = <BlockAuthors<T>>::exists(&curr, authority_id);
+				got_heartbeat || was_author
+			},
 		}
 	}
 
 	/// Returns `true` if a heartbeat has been received for `AuthorityId`
 	/// during the current session. Otherwise `false`.
 	pub fn is_online_in_current_session(authority_id: &T::AuthorityId) -> bool {
-		let current_session = <session::Module<T>>::current_index();
-		<ReceivedHeartbeats<T>>::exists(&current_session, authority_id)
+		let curr = <session::Module<T>>::current_index();
+		let got_heartbeat = <ReceivedHeartbeats<T>>::exists(&curr, authority_id);
+		let was_author = <BlockAuthors<T>>::exists(&curr, authority_id);
+		got_heartbeat || was_author
+	}
+
+	/// Returns `true` if a heartbeat has been received for `AuthorityId`
+	/// during the previous session. Otherwise `false`.
+	pub fn was_online_in_previous_session(authority_id: &T::AuthorityId) -> bool {
+		let curr = <session::Module<T>>::current_index();
+		if curr == 0 {
+			return false;
+		}
+
+		let index = curr - 1;
+		let got_heartbeat = <ReceivedHeartbeats<T>>::exists(&index, authority_id);
+		let was_author = <BlockAuthors<T>>::exists(&index, authority_id);
+		got_heartbeat || was_author
+	}
+
+	/// Disables all validators which haven't been online in the previous session.
+	fn disable_offline_validators() {
+		<Module<T>>::current_session_validators()
+			.iter()
+			.for_each(|(validator_id, authority_id)| {
+				if !Self::was_online_in_previous_session(authority_id) {
+					let _ = T::DisableValidator::disable(validator_id);
+				}
+			});
 	}
 
 	/// Session has just changed.
-	fn new_session() {
+	fn new_session(validators: Vec<(T::AccountId, T::AuthorityId)>) {
+		Self::disable_offline_validators();
+		<CurrentSessionValidators<T>>::put(validators);
+
 		let now = <system::Module<T>>::block_number();
 		<GossipAt<T>>::put(now);
 
@@ -381,9 +436,13 @@ impl<T: Trait> Module<T> {
 			Some(start) => {
 				for index in start..curr {
 					<ReceivedHeartbeats<T>>::remove_prefix(&index);
+					<BlockAuthors<T>>::remove_prefix(&index);
 				}
 			},
-			None => <ReceivedHeartbeats<T>>::remove_prefix(&curr),
+			None => {
+				<ReceivedHeartbeats<T>>::remove_prefix(&curr);
+				<BlockAuthors<T>>::remove_prefix(&curr);
+			},
 		}
 	}
 }
@@ -391,8 +450,18 @@ impl<T: Trait> Module<T> {
 impl<T: Trait> session::OneSessionHandler<T::AccountId> for Module<T> {
 	type Key = <T as Trait>::AuthorityId;
 
-	fn on_new_session<'a, I: 'a>(_changed: bool, _validators: I, _next_validators: I) {
-		Self::new_session();
+	fn on_new_session<'a, I: 'a>(
+		_changed: bool,
+		validators: I,
+		_next_validators: I,
+	)
+		where I: Iterator<Item=(&'a T::AccountId, T::AuthorityId)>
+	{
+		let validators: Vec<(T::AccountId, T::AuthorityId)> = validators
+			.map(|(acc_id, auth_id)| (acc_id.clone(), auth_id))
+			.collect();
+
+		Self::new_session(validators);
 	}
 
 	fn on_disabled(_i: usize) {
@@ -400,6 +469,25 @@ impl<T: Trait> session::OneSessionHandler<T::AccountId> for Module<T> {
 	}
 }
 
+/// Mark nodes which authored automatically as online.
+impl<T: Trait + authorship::Trait> authorship::EventHandler<T::AccountId, T::BlockNumber> for Module<T> {
+	fn note_author(account_id: T::AccountId) {
+		let maybe_authority_id = T::AuthorityIdOf::convert(account_id);
+		if let Some(authority_id) = maybe_authority_id {
+			let current_session = <session::Module<T>>::current_index();
+
+			let exists = <BlockAuthors<T>>::exists(&current_session, &authority_id);
+			if !exists {
+				<BlockAuthors<T>>::insert(&current_session, &authority_id, &true);
+			}
+		}
+	}
+
+	fn note_uncle(_author: T::AccountId, _age: T::BlockNumber) {
+		// ignore
+	}
+}
+
 impl<T: Trait> srml_support::unsigned::ValidateUnsigned for Module<T> {
 	type Call = Call<T>;
 
diff --git a/srml/session/src/lib.rs b/srml/session/src/lib.rs
index a189a91da2848..bd584c1648def 100644
--- a/srml/session/src/lib.rs
+++ b/srml/session/src/lib.rs
@@ -123,7 +123,10 @@ use rstd::{prelude::*, marker::PhantomData, ops::{Sub, Rem}};
 use parity_codec::Decode;
 use sr_primitives::KeyTypeId;
 use sr_primitives::weights::SimpleDispatchInfo;
-use sr_primitives::traits::{Convert, Zero, Member, OpaqueKeys, TypedKey};
+use sr_primitives::traits::{
+	Convert, CurrentSessionKeys as CurrentSessionKeysT, Zero, Member, OpaqueKeys,
+	TypedKey,
+};
 use srml_support::{
 	dispatch::Result, ConsensusEngineId, StorageValue, StorageDoubleMap, for_each_tuple,
 	decl_module, decl_event, decl_storage,
@@ -266,6 +269,9 @@ pub trait Trait: system::Trait {
 	/// A conversion to validator ID to account ID.
 	type ValidatorIdOf: Convert<Self::AccountId, Option<Self::ValidatorId>>;
 
+	/// A conversion of validator ID to account ID.
+	type AccountIdOf: Convert<Self::ValidatorId, Option<Self::AccountId>>;
+
 	/// Indicator for when to end the session.
 	type ShouldEndSession: ShouldEndSession<Self::BlockNumber>;
 
@@ -313,6 +319,9 @@ decl_storage! {
 		/// The first key is always `DEDUP_KEY_PREFIX` to have all the data in the same branch of
 		/// the trie. Having all data in the same branch should prevent slowing down other queries.
 		KeyOwner: double_map hasher(twox_64_concat) Vec<u8>, blake2_256((KeyTypeId, Vec<u8>)) => Option<T::ValidatorId>;
+
+		/// Returns the keys of the current session for all validators.
+		CurrentKeys get(current_keys): Vec<(T::ValidatorId, T::Keys)>;
 	}
 	add_extra_genesis {
 		config(keys): Vec<(T::ValidatorId, T::Keys)>;
@@ -332,6 +341,8 @@ decl_storage! {
 						.expect("genesis config must not contain duplicates; qed");
 				}
 
+				<CurrentKeys<T>>::put(config.keys.clone());
+
 				let initial_validators = T::SelectInitialValidators::select_initial_validators()
 					.unwrap_or_else(|| config.keys.iter().map(|(ref v, _)| v.clone()).collect());
 
@@ -455,6 +466,18 @@ impl<T: Trait> Module<T> {
 		T::SessionHandler::on_new_session::<T::Keys>(changed, &session_keys, &queued_amalgamated);
 	}
 
+	pub fn get_current_keys<Key: Decode + Default + TypedKey>() -> Vec<(T::ValidatorId, Key)> {
+		Self::current_keys()
+			.into_iter()
+			.map(|k| {
+				(k.0,
+				 k.1.get::<Key>(<Key as TypedKey>::KEY_TYPE)
+					 .unwrap_or_default()
+				)
+			})
+			.collect()
+	}
+
 	/// Disable the validator of index `i`.
 	pub fn disable_index(i: usize) {
 		T::SessionHandler::on_disabled(i);
@@ -539,6 +562,25 @@ impl<T: Trait> OnFreeBalanceZero<T::ValidatorId> for Module<T> {
 	}
 }
 
+/// Returns the current session keys.
+pub struct CurrentSessionKeys<T>(rstd::marker::PhantomData<T>);
+
+impl<T: Trait> CurrentSessionKeysT<<T as system::Trait>::AccountId> for CurrentSessionKeys<T> where
+	T::AccountIdOf: Convert<T::ValidatorId, Option<<T as system::Trait>::AccountId>>,
+{
+	fn current_keys<Key>() -> Vec<(<T as system::Trait>::AccountId, Key)>
+		where Key: Decode + Default + TypedKey
+	{
+		<Module<T>>::get_current_keys::<Key>()
+			.into_iter()
+			.map(|(validator_id, keys)| {
+				let account_id = T::AccountIdOf::convert(validator_id).unwrap_or_default();
+				(account_id, keys)
+			})
+			.collect()
+	}
+}
+
 /// Wraps the author-scraping logic for consensus engines that can recover
 /// the canonical index of an author. This then transforms it into the
 /// registering account-ID of that session key index.
diff --git a/srml/session/src/mock.rs b/srml/session/src/mock.rs
index 734f5bbde4bd6..dd5db689f75a5 100644
--- a/srml/session/src/mock.rs
+++ b/srml/session/src/mock.rs
@@ -153,6 +153,7 @@ impl Trait for Test {
 	type ValidatorIdOf = ConvertInto;
 	type Keys = UintAuthorityId;
 	type Event = ();
+	type AccountIdOf = ();
 	type SelectInitialValidators = ();
 }
 
diff --git a/srml/staking/src/lib.rs b/srml/staking/src/lib.rs
index dd540e78b1f36..f0bdd9a3d6916 100644
--- a/srml/staking/src/lib.rs
+++ b/srml/staking/src/lib.rs
@@ -297,7 +297,7 @@ use sr_primitives::Perbill;
 use sr_primitives::weights::SimpleDispatchInfo;
 use sr_primitives::traits::{
 	Convert, Zero, One, StaticLookup, CheckedSub, CheckedShl, Saturating, Bounded,
-	SaturatedConversion, SimpleArithmetic
+	SaturatedConversion, SimpleArithmetic, TypedKey, DisableValidator,
 };
 #[cfg(feature = "std")]
 use sr_primitives::{Serialize, Deserialize};
@@ -480,6 +480,8 @@ pub trait SessionInterface<AccountId>: system::Trait {
 	fn validators() -> Vec<AccountId>;
 	/// Prune historical session tries up to but not including the given index.
 	fn prune_historical_up_to(up_to: session::SessionIndex);
+	/// Get the keys of the current session.
+	fn current_keys<Key: Decode + Default + TypedKey>() -> Vec<(AccountId, Key)>;
 }
 
 impl<T: Trait> SessionInterface<<T as system::Trait>::AccountId> for T where
@@ -491,7 +493,8 @@ impl<T: Trait> SessionInterface<<T as system::Trait>::AccountId> for T where
 	T::SessionHandler: session::SessionHandler<<T as system::Trait>::AccountId>,
 	T::OnSessionEnding: session::OnSessionEnding<<T as system::Trait>::AccountId>,
 	T::SelectInitialValidators: session::SelectInitialValidators<<T as system::Trait>::AccountId>,
-	T::ValidatorIdOf: Convert<<T as system::Trait>::AccountId, Option<<T as system::Trait>::AccountId>>
+	T::ValidatorIdOf: Convert<<T as system::Trait>::AccountId, Option<<T as system::Trait>::AccountId>>,
+	T::AccountIdOf: Convert<<T as system::Trait>::AccountId, Option<<T as system::Trait>::AccountId>>,
 {
 	fn disable_validator(validator: &<T as system::Trait>::AccountId) -> Result<(), ()> {
 		<session::Module<T>>::disable(validator)
@@ -501,6 +504,12 @@ impl<T: Trait> SessionInterface<<T as system::Trait>::AccountId> for T where
 		<session::Module<T>>::validators()
 	}
 
+	fn current_keys<Key>() -> Vec<(<T as system::Trait>::AccountId, Key)>
+		where Key: Decode + Default + TypedKey
+	{
+		<session::Module<T>>::get_current_keys::<Key>()
+	}
+
 	fn prune_historical_up_to(up_to: session::SessionIndex) {
 		<session::historical::Module<T>>::prune_up_to(up_to);
 	}
@@ -1438,6 +1447,16 @@ impl<T: Trait> OnFreeBalanceZero<T::AccountId> for Module<T> {
 	}
 }
 
+/// A `Convert` implementation that finds the controller account of the given stash account,
+/// if any.
+pub struct DisableValidatorInterface<T>(rstd::marker::PhantomData<T>);
+
+impl<T: Trait> DisableValidator<T::AccountId> for DisableValidatorInterface<T> {
+	fn disable(account_id: &T::AccountId) -> Result<(), ()> {
+		T::SessionInterface::disable_validator(account_id)
+	}
+}
+
 /// Add reward points to block authors:
 /// * 20 points to the block producer for producing a (non-uncle) block in the relay chain,
 /// * 2 points to the block producer for each reference to a previously unreferenced uncle, and
@@ -1452,6 +1471,16 @@ impl<T: Trait + authorship::Trait> authorship::EventHandler<T::AccountId, T::Blo
 	}
 }
 
+/// A `Convert` implementation that finds the controller account of the
+/// given stash account, if any.
+pub struct ControllerOf<T>(rstd::marker::PhantomData<T>);
+
+impl<T: Trait> Convert<T::AccountId, Option<T::AccountId>> for ControllerOf<T> {
+	fn convert(stash: T::AccountId) -> Option<T::AccountId> {
+		<Module<T>>::bonded(&stash)
+	}
+}
+
 // This is guarantee not to overflow on whatever values.
 // `num` must be inferior to `den` otherwise it will be reduce to `den`.
 fn multiply_by_rational<N>(value: N, num: u32, den: u32) -> N
diff --git a/srml/staking/src/mock.rs b/srml/staking/src/mock.rs
index 344ef70e3b6f4..abb7bf99a7d92 100644
--- a/srml/staking/src/mock.rs
+++ b/srml/staking/src/mock.rs
@@ -157,6 +157,7 @@ impl session::Trait for Test {
 	type ValidatorId = AccountId;
 	type ValidatorIdOf = crate::StashOf<Test>;
 	type SelectInitialValidators = Staking;
+	type AccountIdOf = crate::ControllerOf<Self>;
 }
 
 impl session::historical::Trait for Test {