diff --git a/modules/incentives/src/lib.rs b/modules/incentives/src/lib.rs
index 6a13855b7..b7a90da49 100644
--- a/modules/incentives/src/lib.rs
+++ b/modules/incentives/src/lib.rs
@@ -42,7 +42,7 @@
 use frame_support::{pallet_prelude::*, transactional, PalletId};
 use frame_system::pallet_prelude::*;
 use module_support::{DEXIncentives, EmergencyShutdown, FractionalRate, IncentivesManager, PoolId, Rate};
-use orml_traits::{Handler, Happened, MultiCurrency, RewardHandler};
+use orml_traits::{Handler, MultiCurrency, RewardHandler};
 use primitives::{Amount, Balance, CurrencyId};
 use sp_runtime::{
 	traits::{AccountIdConversion, UniqueSaturatedInto, Zero},
@@ -619,15 +619,15 @@ impl<T: Config> Handler<(T::AccountId, Balance)> for OnEarningUnbonded<T> {
 }
 
 pub struct OnNomineesElectionBonded<T>(sp_std::marker::PhantomData<T>);
-impl<T: Config> Happened<(T::AccountId, Balance)> for OnNomineesElectionBonded<T> {
-	fn happened((who, amount): &(T::AccountId, Balance)) {
-		let _ = <orml_rewards::Pallet<T>>::add_share(who, &PoolId::NomineesElection, *amount);
+impl<T: Config> Handler<(T::AccountId, Balance)> for OnNomineesElectionBonded<T> {
+	fn handle((who, amount): &(T::AccountId, Balance)) -> DispatchResult {
+		<orml_rewards::Pallet<T>>::add_share(who, &PoolId::NomineesElection, *amount)
 	}
 }
 
 pub struct OnNomineesElectionUnbonded<T>(sp_std::marker::PhantomData<T>);
-impl<T: Config> Happened<(T::AccountId, Balance)> for OnNomineesElectionUnbonded<T> {
-	fn happened((who, amount): &(T::AccountId, Balance)) {
-		let _ = <orml_rewards::Pallet<T>>::remove_share(who, &PoolId::NomineesElection, *amount);
+impl<T: Config> Handler<(T::AccountId, Balance)> for OnNomineesElectionUnbonded<T> {
+	fn handle((who, amount): &(T::AccountId, Balance)) -> DispatchResult {
+		<orml_rewards::Pallet<T>>::remove_share(who, &PoolId::NomineesElection, *amount)
 	}
 }
diff --git a/modules/incentives/src/tests.rs b/modules/incentives/src/tests.rs
index 9ef12a22b..85e3651ed 100644
--- a/modules/incentives/src/tests.rs
+++ b/modules/incentives/src/tests.rs
@@ -1342,7 +1342,7 @@ fn claim_reward_deduction_currency_works() {
 #[test]
 fn nominees_election_should_work() {
 	ExtBuilder::default().build().execute_with(|| {
-		OnNomineesElectionBonded::<Runtime>::happened(&(ALICE::get(), 80));
+		OnNomineesElectionBonded::<Runtime>::handle(&(ALICE::get(), 80));
 		assert_eq!(
 			RewardsModule::pool_infos(PoolId::NomineesElection),
 			PoolInfo {
@@ -1355,7 +1355,7 @@ fn nominees_election_should_work() {
 			(80, Default::default())
 		);
 
-		OnNomineesElectionUnbonded::<Runtime>::happened(&(ALICE::get(), 20));
+		OnNomineesElectionUnbonded::<Runtime>::handle(&(ALICE::get(), 20));
 		assert_eq!(
 			RewardsModule::pool_infos(PoolId::NomineesElection),
 			PoolInfo {
@@ -1368,7 +1368,7 @@ fn nominees_election_should_work() {
 			(60, Default::default())
 		);
 
-		OnNomineesElectionUnbonded::<Runtime>::happened(&(ALICE::get(), 60));
+		OnNomineesElectionUnbonded::<Runtime>::handle(&(ALICE::get(), 60));
 		assert_eq!(
 			RewardsModule::pool_infos(PoolId::NomineesElection),
 			PoolInfo { ..Default::default() }
diff --git a/modules/nominees-election/src/lib.rs b/modules/nominees-election/src/lib.rs
index 16d5c2dab..af6d087ab 100644
--- a/modules/nominees-election/src/lib.rs
+++ b/modules/nominees-election/src/lib.rs
@@ -27,7 +27,7 @@ use frame_support::{
 };
 use frame_system::pallet_prelude::*;
 use module_support::NomineesProvider;
-use orml_traits::{BasicCurrency, BasicLockableCurrency, Happened};
+use orml_traits::{BasicCurrency, BasicLockableCurrency, Handler};
 use primitives::{
 	bonding::{self, BondingController},
 	Balance, EraIndex,
@@ -84,10 +84,10 @@ pub mod module {
 		type GovernanceOrigin: EnsureOrigin<Self::RuntimeOrigin>;
 
 		/// Callback when an account bonded.
-		type OnBonded: Happened<(Self::AccountId, Balance)>;
+		type OnBonded: Handler<(Self::AccountId, Balance)>;
 
 		/// Callback when an account unbonded.
-		type OnUnbonded: Happened<(Self::AccountId, Balance)>;
+		type OnUnbonded: Handler<(Self::AccountId, Balance)>;
 
 		/// Current era.
 		type CurrentEra: Get<EraIndex>;
@@ -199,7 +199,7 @@ pub mod module {
 
 				Self::update_votes(change.old, &old_nominations, change.new, &old_nominations);
 
-				T::OnBonded::happened(&(who.clone(), change.change));
+				T::OnBonded::handle(&(who.clone(), change.change))?;
 
 				Self::deposit_event(Event::Bond {
 					who,
@@ -222,7 +222,7 @@ pub mod module {
 
 				Self::update_votes(change.old, &old_nominations, change.new, &old_nominations);
 
-				T::OnUnbonded::happened(&(who.clone(), change.change));
+				T::OnUnbonded::handle(&(who.clone(), change.change))?;
 
 				Self::deposit_event(Event::Unbond {
 					who,
@@ -245,7 +245,7 @@ pub mod module {
 
 				Self::update_votes(change.old, &old_nominations, change.new, &old_nominations);
 
-				T::OnBonded::happened(&(who.clone(), change.change));
+				T::OnBonded::handle(&(who.clone(), change.change))?;
 
 				Self::deposit_event(Event::Rebond {
 					who,
diff --git a/modules/nominees-election/src/mock.rs b/modules/nominees-election/src/mock.rs
index defa1d390..1e4f7ee6a 100644
--- a/modules/nominees-election/src/mock.rs
+++ b/modules/nominees-election/src/mock.rs
@@ -130,8 +130,8 @@ parameter_types! {
 }
 
 pub struct MockOnBonded;
-impl Happened<(AccountId, Balance)> for MockOnBonded {
-	fn happened(info: &(AccountId, Balance)) {
+impl Handler<(AccountId, Balance)> for MockOnBonded {
+	fn handle(info: &(AccountId, Balance)) -> DispatchResult {
 		let (account_id, amount) = info;
 		Shares::mutate(|v| {
 			let mut old_map = v.clone();
@@ -143,12 +143,13 @@ impl Happened<(AccountId, Balance)> for MockOnBonded {
 
 			*v = old_map;
 		});
+		Ok(())
 	}
 }
 
 pub struct MockOnUnbonded;
-impl Happened<(AccountId, Balance)> for MockOnUnbonded {
-	fn happened(info: &(AccountId, Balance)) {
+impl Handler<(AccountId, Balance)> for MockOnUnbonded {
+	fn handle(info: &(AccountId, Balance)) -> DispatchResult {
 		let (account_id, amount) = info;
 		Shares::mutate(|v| {
 			let mut old_map = v.clone();
@@ -160,6 +161,7 @@ impl Happened<(AccountId, Balance)> for MockOnUnbonded {
 
 			*v = old_map;
 		});
+		Ok(())
 	}
 }