diff --git a/runtime/kusama/src/weights/runtime_parachains_configuration.rs b/runtime/kusama/src/weights/runtime_parachains_configuration.rs
index ae840f37752d..93c9e5e9c866 100644
--- a/runtime/kusama/src/weights/runtime_parachains_configuration.rs
+++ b/runtime/kusama/src/weights/runtime_parachains_configuration.rs
@@ -16,7 +16,7 @@
 //! Autogenerated weights for `runtime_parachains::configuration`
 //!
 //! THIS FILE WAS AUTO-GENERATED USING THE SUBSTRATE BENCHMARK CLI VERSION 4.0.0-dev
-//! DATE: 2021-09-17, STEPS: `50`, REPEAT: 20, LOW RANGE: `[]`, HIGH RANGE: `[]`
+//! DATE: 2021-12-16, STEPS: `50`, REPEAT: 20, LOW RANGE: `[]`, HIGH RANGE: `[]`
 //! EXECUTION: Some(Wasm), WASM-EXECUTION: Compiled, CHAIN: Some("kusama-dev"), DB CACHE: 128
 
 // Executed Command:
@@ -33,7 +33,6 @@
 // --header=./file_header.txt
 // --output=./runtime/kusama/src/weights/runtime_parachains_configuration.rs
 
-
 #![cfg_attr(rustfmt, rustfmt_skip)]
 #![allow(unused_parens)]
 #![allow(unused_imports)]
@@ -44,35 +43,35 @@ use sp_std::marker::PhantomData;
 /// Weight functions for `runtime_parachains::configuration`.
 pub struct WeightInfo<T>(PhantomData<T>);
 impl<T: frame_system::Config> runtime_parachains::configuration::WeightInfo for WeightInfo<T> {
-	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: Configuration ActiveConfig (r:1 w:0)
+	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
 	fn set_config_with_block_number() -> Weight {
-		(12_378_000 as Weight)
+		(8_240_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(3 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
-	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: Configuration ActiveConfig (r:1 w:0)
+	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
 	fn set_config_with_u32() -> Weight {
-		(12_384_000 as Weight)
+		(8_123_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(3 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
-	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: Configuration ActiveConfig (r:1 w:0)
+	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
 	fn set_config_with_option_u32() -> Weight {
-		(12_746_000 as Weight)
+		(8_547_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(3 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
-	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: Configuration ActiveConfig (r:1 w:0)
+	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
 	fn set_config_with_weight() -> Weight {
-		(12_563_000 as Weight)
+		(8_379_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(3 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
@@ -80,11 +79,11 @@ impl<T: frame_system::Config> runtime_parachains::configuration::WeightInfo for
 	fn set_hrmp_open_request_ttl() -> Weight {
 		(2_000_000_000_000 as Weight)
 	}
-	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: Configuration ActiveConfig (r:1 w:0)
+	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
 	fn set_config_with_balance() -> Weight {
-		(12_644_000 as Weight)
+		(8_400_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(3 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
diff --git a/runtime/parachains/src/configuration.rs b/runtime/parachains/src/configuration.rs
index f67f96ba8b3e..8b18c7d59559 100644
--- a/runtime/parachains/src/configuration.rs
+++ b/runtime/parachains/src/configuration.rs
@@ -33,7 +33,6 @@ pub use pallet::*;
 
 pub mod migration;
 
-#[allow(dead_code)]
 const LOG_TARGET: &str = "runtime::configuration";
 
 /// All configuration of the runtime with respect to parachains and parathreads.
@@ -361,9 +360,22 @@ pub mod pallet {
 		StorageValue<_, HostConfiguration<T::BlockNumber>, ValueQuery>;
 
 	/// Pending configuration (if any) for the next session.
+	///
+	/// DEPRECATED: This is no longer used, and will be removed in the future.
 	#[pallet::storage]
 	pub(crate) type PendingConfig<T: Config> =
-		StorageMap<_, Twox64Concat, SessionIndex, HostConfiguration<T::BlockNumber>>;
+		StorageMap<_, Twox64Concat, SessionIndex, migration::v1::HostConfiguration<T::BlockNumber>>;
+
+	/// Pending configuration changes.
+	///
+	/// This is a list of configuration changes, each with a session index at which it should
+	/// be applied.
+	///
+	/// The list is sorted ascending by session index. Also, this list can only contain at most
+	/// 2 items: for the next session and for the `scheduled_session`.
+	#[pallet::storage]
+	pub(crate) type PendingConfigs<T: Config> =
+		StorageValue<_, Vec<(SessionIndex, HostConfiguration<T::BlockNumber>)>, ValueQuery>;
 
 	#[pallet::genesis_config]
 	pub struct GenesisConfig<T: Config> {
@@ -398,7 +410,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.validation_upgrade_frequency, new) != new
+				config.validation_upgrade_frequency = new;
 			});
 			Ok(())
 		}
@@ -414,7 +426,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.validation_upgrade_delay, new) != new
+				config.validation_upgrade_delay = new;
 			});
 			Ok(())
 		}
@@ -430,7 +442,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.code_retention_period, new) != new
+				config.code_retention_period = new;
 			});
 			Ok(())
 		}
@@ -444,7 +456,7 @@ pub mod pallet {
 			ensure_root(origin)?;
 			ensure!(new <= MAX_CODE_SIZE, Error::<T>::InvalidNewValue);
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.max_code_size, new) != new
+				config.max_code_size = new;
 			});
 			Ok(())
 		}
@@ -458,7 +470,7 @@ pub mod pallet {
 			ensure_root(origin)?;
 			ensure!(new <= MAX_POV_SIZE, Error::<T>::InvalidNewValue);
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.max_pov_size, new) != new
+				config.max_pov_size = new;
 			});
 			Ok(())
 		}
@@ -472,7 +484,7 @@ pub mod pallet {
 			ensure_root(origin)?;
 			ensure!(new <= MAX_HEAD_DATA_SIZE, Error::<T>::InvalidNewValue);
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.max_head_data_size, new) != new
+				config.max_head_data_size = new;
 			});
 			Ok(())
 		}
@@ -485,7 +497,7 @@ pub mod pallet {
 		pub fn set_parathread_cores(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.parathread_cores, new) != new
+				config.parathread_cores = new;
 			});
 			Ok(())
 		}
@@ -498,7 +510,7 @@ pub mod pallet {
 		pub fn set_parathread_retries(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.parathread_retries, new) != new
+				config.parathread_retries = new;
 			});
 			Ok(())
 		}
@@ -517,7 +529,7 @@ pub mod pallet {
 			ensure!(!new.is_zero(), Error::<T>::InvalidNewValue);
 
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.group_rotation_frequency, new) != new
+				config.group_rotation_frequency = new;
 			});
 			Ok(())
 		}
@@ -536,7 +548,7 @@ pub mod pallet {
 			ensure!(!new.is_zero(), Error::<T>::InvalidNewValue);
 
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.chain_availability_period, new) != new
+				config.chain_availability_period = new;
 			});
 			Ok(())
 		}
@@ -555,7 +567,7 @@ pub mod pallet {
 			ensure!(!new.is_zero(), Error::<T>::InvalidNewValue);
 
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.thread_availability_period, new) != new
+				config.thread_availability_period = new;
 			});
 			Ok(())
 		}
@@ -568,7 +580,7 @@ pub mod pallet {
 		pub fn set_scheduling_lookahead(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.scheduling_lookahead, new) != new
+				config.scheduling_lookahead = new;
 			});
 			Ok(())
 		}
@@ -584,7 +596,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.max_validators_per_core, new) != new
+				config.max_validators_per_core = new;
 			});
 			Ok(())
 		}
@@ -597,7 +609,7 @@ pub mod pallet {
 		pub fn set_max_validators(origin: OriginFor<T>, new: Option<u32>) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.max_validators, new) != new
+				config.max_validators = new;
 			});
 			Ok(())
 		}
@@ -610,7 +622,7 @@ pub mod pallet {
 		pub fn set_dispute_period(origin: OriginFor<T>, new: SessionIndex) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.dispute_period, new) != new
+				config.dispute_period = new;
 			});
 			Ok(())
 		}
@@ -626,8 +638,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.dispute_post_conclusion_acceptance_period, new) !=
-					new
+				config.dispute_post_conclusion_acceptance_period = new;
 			});
 			Ok(())
 		}
@@ -640,7 +651,7 @@ pub mod pallet {
 		pub fn set_dispute_max_spam_slots(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.dispute_max_spam_slots, new) != new
+				config.dispute_max_spam_slots = new;
 			});
 			Ok(())
 		}
@@ -656,7 +667,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.dispute_conclusion_by_time_out_period, new) != new
+				config.dispute_conclusion_by_time_out_period = new;
 			});
 			Ok(())
 		}
@@ -673,7 +684,7 @@ pub mod pallet {
 			ensure!(!new.is_zero(), Error::<T>::InvalidNewValue);
 
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.no_show_slots, new) != new
+				config.no_show_slots = new;
 			});
 			Ok(())
 		}
@@ -686,7 +697,7 @@ pub mod pallet {
 		pub fn set_n_delay_tranches(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.n_delay_tranches, new) != new
+				config.n_delay_tranches = new;
 			});
 			Ok(())
 		}
@@ -699,7 +710,7 @@ pub mod pallet {
 		pub fn set_zeroth_delay_tranche_width(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.zeroth_delay_tranche_width, new) != new
+				config.zeroth_delay_tranche_width = new;
 			});
 			Ok(())
 		}
@@ -712,7 +723,7 @@ pub mod pallet {
 		pub fn set_needed_approvals(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.needed_approvals, new) != new
+				config.needed_approvals = new;
 			});
 			Ok(())
 		}
@@ -725,7 +736,7 @@ pub mod pallet {
 		pub fn set_relay_vrf_modulo_samples(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.relay_vrf_modulo_samples, new) != new
+				config.relay_vrf_modulo_samples = new;
 			});
 			Ok(())
 		}
@@ -738,7 +749,7 @@ pub mod pallet {
 		pub fn set_max_upward_queue_count(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.max_upward_queue_count, new) != new
+				config.max_upward_queue_count = new;
 			});
 			Ok(())
 		}
@@ -751,7 +762,7 @@ pub mod pallet {
 		pub fn set_max_upward_queue_size(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.max_upward_queue_size, new) != new
+				config.max_upward_queue_size = new;
 			});
 			Ok(())
 		}
@@ -764,7 +775,7 @@ pub mod pallet {
 		pub fn set_max_downward_message_size(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.max_downward_message_size, new) != new
+				config.max_downward_message_size = new;
 			});
 			Ok(())
 		}
@@ -777,7 +788,7 @@ pub mod pallet {
 		pub fn set_ump_service_total_weight(origin: OriginFor<T>, new: Weight) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.ump_service_total_weight, new) != new
+				config.ump_service_total_weight = new;
 			});
 			Ok(())
 		}
@@ -790,7 +801,7 @@ pub mod pallet {
 		pub fn set_max_upward_message_size(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.max_upward_message_size, new) != new
+				config.max_upward_message_size = new;
 			});
 			Ok(())
 		}
@@ -806,7 +817,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.max_upward_message_num_per_candidate, new) != new
+				config.max_upward_message_num_per_candidate = new;
 			});
 			Ok(())
 		}
@@ -830,7 +841,7 @@ pub mod pallet {
 		pub fn set_hrmp_sender_deposit(origin: OriginFor<T>, new: Balance) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.hrmp_sender_deposit, new) != new
+				config.hrmp_sender_deposit = new;
 			});
 			Ok(())
 		}
@@ -844,7 +855,7 @@ pub mod pallet {
 		pub fn set_hrmp_recipient_deposit(origin: OriginFor<T>, new: Balance) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.hrmp_recipient_deposit, new) != new
+				config.hrmp_recipient_deposit = new;
 			});
 			Ok(())
 		}
@@ -857,7 +868,7 @@ pub mod pallet {
 		pub fn set_hrmp_channel_max_capacity(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.hrmp_channel_max_capacity, new) != new
+				config.hrmp_channel_max_capacity = new;
 			});
 			Ok(())
 		}
@@ -870,7 +881,7 @@ pub mod pallet {
 		pub fn set_hrmp_channel_max_total_size(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.hrmp_channel_max_total_size, new) != new
+				config.hrmp_channel_max_total_size = new;
 			});
 			Ok(())
 		}
@@ -886,7 +897,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.hrmp_max_parachain_inbound_channels, new) != new
+				config.hrmp_max_parachain_inbound_channels = new;
 			});
 			Ok(())
 		}
@@ -902,7 +913,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.hrmp_max_parathread_inbound_channels, new) != new
+				config.hrmp_max_parathread_inbound_channels = new;
 			});
 			Ok(())
 		}
@@ -915,7 +926,7 @@ pub mod pallet {
 		pub fn set_hrmp_channel_max_message_size(origin: OriginFor<T>, new: u32) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.hrmp_channel_max_message_size, new) != new
+				config.hrmp_channel_max_message_size = new;
 			});
 			Ok(())
 		}
@@ -931,7 +942,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.hrmp_max_parachain_outbound_channels, new) != new
+				config.hrmp_max_parachain_outbound_channels = new;
 			});
 			Ok(())
 		}
@@ -947,7 +958,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.hrmp_max_parathread_outbound_channels, new) != new
+				config.hrmp_max_parathread_outbound_channels = new;
 			});
 			Ok(())
 		}
@@ -963,7 +974,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.hrmp_max_message_num_per_candidate, new) != new
+				config.hrmp_max_message_num_per_candidate = new;
 			});
 			Ok(())
 		}
@@ -976,7 +987,7 @@ pub mod pallet {
 		pub fn set_ump_max_individual_weight(origin: OriginFor<T>, new: Weight) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.ump_max_individual_weight, new) != new
+				config.ump_max_individual_weight = new;
 			});
 			Ok(())
 		}
@@ -990,7 +1001,7 @@ pub mod pallet {
 		pub fn set_pvf_checking_enabled(origin: OriginFor<T>, new: bool) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.pvf_checking_enabled, new) != new
+				config.pvf_checking_enabled = new;
 			});
 			Ok(())
 		}
@@ -1003,7 +1014,7 @@ pub mod pallet {
 		pub fn set_pvf_voting_ttl(origin: OriginFor<T>, new: SessionIndex) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.pvf_voting_ttl, new) != new
+				config.pvf_voting_ttl = new;
 			});
 			Ok(())
 		}
@@ -1020,7 +1031,7 @@ pub mod pallet {
 		) -> DispatchResult {
 			ensure_root(origin)?;
 			Self::update_config_member(|config| {
-				sp_std::mem::replace(&mut config.minimum_validation_upgrade_delay, new) != new
+				config.minimum_validation_upgrade_delay = new;
 			});
 			Ok(())
 		}
@@ -1054,9 +1065,28 @@ impl<T: Config> Pallet<T> {
 
 	/// Called by the initializer to note that a new session has started.
 	pub(crate) fn initializer_on_new_session(session_index: &SessionIndex) {
-		if let Some(pending) = <Self as Store>::PendingConfig::take(session_index) {
-			<Self as Store>::ActiveConfig::set(pending);
+		let pending_configs = <PendingConfigs<T>>::get();
+		if pending_configs.is_empty() {
+			return
 		}
+
+		let (past_and_present, future) = pending_configs
+			.into_iter()
+			.partition::<Vec<_>, _>(|&(apply_at_session, _)| apply_at_session <= *session_index);
+
+		if past_and_present.len() > 1 {
+			// This should never happen since we schedule configuration changes only into the future
+			// sessions and this handler called for each session change.
+			log::error!(
+				target: LOG_TARGET,
+				"Skipping applying configuration changes scheduled sessions in the past",
+			);
+		}
+		if let Some((_, pending)) = past_and_present.last() {
+			<Self as Store>::ActiveConfig::put(pending);
+		}
+
+		<PendingConfigs<T>>::put(future);
 	}
 
 	/// Return the session index that should be used for any future scheduled changes.
@@ -1076,24 +1106,82 @@ impl<T: Config> Pallet<T> {
 	// duplicated code (making this function to show up in the top of heaviest functions) only for
 	// the sake of essentially avoiding an indirect call. Doesn't worth it.
 	#[inline(never)]
-	fn update_config_member(updater: impl FnOnce(&mut HostConfiguration<T::BlockNumber>) -> bool) {
+	fn update_config_member(updater: impl FnOnce(&mut HostConfiguration<T::BlockNumber>)) {
+		let mut pending_configs = <PendingConfigs<T>>::get();
+
+		// 1. pending_configs = []
+		//    No pending configuration changes.
+		//
+		//    That means we should use the active config as the base configuration. We will insert
+		//    the new pending configuration as (cur+2, new_config) into the list.
+		//
+		// 2. pending_configs = [(cur+2, X)]
+		//    There is a configuration that is pending for the scheduled session.
+		//
+		//    We will use X as the base configuration. We can update the pending configuration X
+		//    directly.
+		//
+		// 3. pending_configs = [(cur+1, X)]
+		//    There is a pending configuration scheduled and it will be applied in the next session.
+		//
+		//    We will use X as the base configuration. We need to schedule a new configuration change
+		//    for the `scheduled_session` and use X as the base for the new configuration.
+		//
+		// 4. pending_configs = [(cur+1, X), (cur+2, Y)]
+		//    There is a pending configuration change in the next session and for the scheduled
+		//    session. Due to case №3, we can be sure that Y is based on top of X. This means we
+		//    can use Y as the base configuration and update Y directly.
+		//
+		// There cannot be (cur, X) because those are applied in the session change handler for the
+		// current session.
+
+		// First, we need to decide what we should use as the base configuration.
+		let mut base_config = pending_configs
+			.last()
+			.map(|&(_, ref config)| config.clone())
+			.unwrap_or_else(Self::config);
+
+		// Now, we need to decide what the new configuration should be.
+		updater(&mut base_config);
+
 		let scheduled_session = Self::scheduled_session();
-		let pending = <Self as Store>::PendingConfig::get(scheduled_session);
-		let mut prev = pending.unwrap_or_else(Self::config);
 
-		if updater(&mut prev) {
-			<Self as Store>::PendingConfig::insert(scheduled_session, prev);
+		if let Some(&mut (_, ref mut config)) = pending_configs
+			.iter_mut()
+			.find(|&&mut (apply_at_session, _)| apply_at_session >= scheduled_session)
+		{
+			*config = base_config;
+		} else {
+			// We are scheduling a new configuration change for the scheduled session.
+			pending_configs.push((scheduled_session, base_config));
 		}
+
+		<PendingConfigs<T>>::put(pending_configs);
 	}
 }
 
 #[cfg(test)]
 mod tests {
 	use super::*;
-	use crate::mock::{new_test_ext, Configuration, Origin};
+	use crate::mock::{new_test_ext, Configuration, Origin, ParasShared};
 
 	use frame_support::assert_ok;
 
+	fn on_new_session(session_index: SessionIndex) {
+		ParasShared::set_session_index(session_index);
+		Configuration::initializer_on_new_session(&session_index);
+	}
+
+	#[test]
+	fn scheduled_session_is_two_sessions_from_now() {
+		new_test_ext(Default::default()).execute_with(|| {
+			// The logic here is really tested only with scheduled_session = 2. It should work
+			// with other values, but that should receive a more rigorious testing.
+			on_new_session(1);
+			assert_eq!(Configuration::scheduled_session(), 3);
+		});
+	}
+
 	#[test]
 	fn config_changes_after_2_session_boundary() {
 		new_test_ext(Default::default()).execute_with(|| {
@@ -1104,21 +1192,146 @@ mod tests {
 
 			assert_ok!(Configuration::set_validation_upgrade_delay(Origin::root(), 100));
 
+			// Verify that the current configuration has not changed and that there is a scheduled
+			// change for the SESSION_DELAY sessions in advance.
 			assert_eq!(Configuration::config(), old_config);
-			assert_eq!(<Configuration as Store>::PendingConfig::get(1), None);
+			assert_eq!(<Configuration as Store>::PendingConfigs::get(), vec![(2, config.clone())]);
 
-			Configuration::initializer_on_new_session(&1);
+			on_new_session(1);
 
+			// One session has passed, we should be still waiting for the pending configuration.
 			assert_eq!(Configuration::config(), old_config);
-			assert_eq!(<Configuration as Store>::PendingConfig::get(2), Some(config.clone()));
+			assert_eq!(<Configuration as Store>::PendingConfigs::get(), vec![(2, config.clone())]);
 
-			Configuration::initializer_on_new_session(&2);
+			on_new_session(2);
 
 			assert_eq!(Configuration::config(), config);
-			assert_eq!(<Configuration as Store>::PendingConfig::get(3), None);
+			assert_eq!(<Configuration as Store>::PendingConfigs::get(), vec![]);
 		})
 	}
 
+	#[test]
+	fn consecutive_changes_within_one_session() {
+		new_test_ext(Default::default()).execute_with(|| {
+			let old_config = Configuration::config();
+			let mut config = old_config.clone();
+			config.validation_upgrade_delay = 100;
+			config.validation_upgrade_frequency = 100;
+			assert!(old_config != config);
+
+			assert_ok!(Configuration::set_validation_upgrade_delay(Origin::root(), 100));
+			assert_ok!(Configuration::set_validation_upgrade_frequency(Origin::root(), 100));
+			assert_eq!(Configuration::config(), old_config);
+			assert_eq!(<Configuration as Store>::PendingConfigs::get(), vec![(2, config.clone())]);
+
+			on_new_session(1);
+
+			assert_eq!(Configuration::config(), old_config);
+			assert_eq!(<Configuration as Store>::PendingConfigs::get(), vec![(2, config.clone())]);
+
+			on_new_session(2);
+
+			assert_eq!(Configuration::config(), config);
+			assert_eq!(<Configuration as Store>::PendingConfigs::get(), vec![]);
+		});
+	}
+
+	#[test]
+	fn pending_next_session_but_we_upgrade_once_more() {
+		new_test_ext(Default::default()).execute_with(|| {
+			let initial_config = Configuration::config();
+			let intermediate_config =
+				HostConfiguration { validation_upgrade_delay: 100, ..initial_config.clone() };
+			let final_config = HostConfiguration {
+				validation_upgrade_delay: 100,
+				validation_upgrade_frequency: 99,
+				..initial_config.clone()
+			};
+
+			assert_ok!(Configuration::set_validation_upgrade_delay(Origin::root(), 100));
+			assert_eq!(Configuration::config(), initial_config);
+			assert_eq!(
+				<Configuration as Store>::PendingConfigs::get(),
+				vec![(2, intermediate_config.clone())]
+			);
+
+			on_new_session(1);
+
+			// We are still waiting until the pending configuration is applied and we add another
+			// update.
+			assert_ok!(Configuration::set_validation_upgrade_frequency(Origin::root(), 99));
+
+			// This should result in yet another configiguration change scheduled.
+			assert_eq!(Configuration::config(), initial_config);
+			assert_eq!(
+				<Configuration as Store>::PendingConfigs::get(),
+				vec![(2, intermediate_config.clone()), (3, final_config.clone())]
+			);
+
+			on_new_session(2);
+
+			assert_eq!(Configuration::config(), intermediate_config);
+			assert_eq!(
+				<Configuration as Store>::PendingConfigs::get(),
+				vec![(3, final_config.clone())]
+			);
+
+			on_new_session(3);
+
+			assert_eq!(Configuration::config(), final_config);
+			assert_eq!(<Configuration as Store>::PendingConfigs::get(), vec![]);
+		});
+	}
+
+	#[test]
+	fn scheduled_session_config_update_while_next_session_pending() {
+		new_test_ext(Default::default()).execute_with(|| {
+			let initial_config = Configuration::config();
+			let intermediate_config =
+				HostConfiguration { validation_upgrade_delay: 100, ..initial_config.clone() };
+			let final_config = HostConfiguration {
+				validation_upgrade_delay: 100,
+				validation_upgrade_frequency: 99,
+				code_retention_period: 98,
+				..initial_config.clone()
+			};
+
+			assert_ok!(Configuration::set_validation_upgrade_delay(Origin::root(), 100));
+			assert_eq!(Configuration::config(), initial_config);
+			assert_eq!(
+				<Configuration as Store>::PendingConfigs::get(),
+				vec![(2, intermediate_config.clone())]
+			);
+
+			on_new_session(1);
+
+			// The second call should fall into the case where we already have a pending config
+			// update for the scheduled_session, but we want to update it once more.
+			assert_ok!(Configuration::set_validation_upgrade_frequency(Origin::root(), 99));
+			assert_ok!(Configuration::set_code_retention_period(Origin::root(), 98));
+
+			// This should result in yet another configiguration change scheduled.
+			assert_eq!(Configuration::config(), initial_config);
+			assert_eq!(
+				<Configuration as Store>::PendingConfigs::get(),
+				vec![(2, intermediate_config.clone()), (3, final_config.clone())]
+			);
+
+			on_new_session(2);
+
+			assert_eq!(Configuration::config(), intermediate_config);
+			assert_eq!(
+				<Configuration as Store>::PendingConfigs::get(),
+				vec![(3, final_config.clone())]
+			);
+
+			on_new_session(3);
+
+			assert_eq!(Configuration::config(), final_config);
+			assert_eq!(<Configuration as Store>::PendingConfigs::get(), vec![]);
+		});
+	}
+
 	#[test]
 	fn setting_pending_config_members() {
 		new_test_ext(Default::default()).execute_with(|| {
@@ -1345,8 +1558,8 @@ mod tests {
 			.unwrap();
 
 			assert_eq!(
-				<Configuration as Store>::PendingConfig::get(shared::SESSION_DELAY),
-				Some(new_config)
+				<Configuration as Store>::PendingConfigs::get(),
+				vec![(shared::SESSION_DELAY, new_config)],
 			);
 		})
 	}
@@ -1358,15 +1571,6 @@ mod tests {
 		});
 	}
 
-	#[test]
-	fn setting_config_to_same_as_current_is_noop() {
-		new_test_ext(Default::default()).execute_with(|| {
-			Configuration::set_validation_upgrade_delay(Origin::root(), Default::default())
-				.unwrap();
-			assert!(<Configuration as Store>::PendingConfig::get(shared::SESSION_DELAY).is_none())
-		});
-	}
-
 	#[test]
 	fn verify_externally_accessible() {
 		// This test verifies that the value can be accessed through the well known keys and the
diff --git a/runtime/parachains/src/configuration/migration.rs b/runtime/parachains/src/configuration/migration.rs
index ed3a8a79d727..2d84dc5ec323 100644
--- a/runtime/parachains/src/configuration/migration.rs
+++ b/runtime/parachains/src/configuration/migration.rs
@@ -19,6 +19,7 @@
 use crate::configuration::{self, Config, Pallet, Store};
 use frame_support::{pallet_prelude::*, traits::StorageVersion, weights::Weight};
 use frame_system::pallet_prelude::BlockNumberFor;
+use sp_std::prelude::*;
 
 /// The current storage version.
 ///
@@ -36,13 +37,15 @@ pub fn migrate_to_latest<T: Config>() -> Weight {
 	weight
 }
 
-mod v1 {
+pub mod v1 {
 	use super::*;
 	use primitives::v1::{Balance, SessionIndex};
 
 	// Copied over from configuration.rs @ 656dd280f266dc56bd0cf1dbe3ca232960912f34 and removed
 	// all the comments.
-	#[derive(parity_scale_codec::Encode, parity_scale_codec::Decode, Debug)]
+	#[derive(
+		parity_scale_codec::Encode, parity_scale_codec::Decode, scale_info::TypeInfo, Debug, Clone,
+	)]
 	pub struct HostConfiguration<BlockNumber> {
 		pub max_code_size: u32,
 		pub max_head_data_size: u32,
@@ -193,6 +196,11 @@ minimum_validation_upgrade_delay: pre.chain_availability_period + 10u32.into(),
 		}
 	};
 
+	let mut weight = 0;
+
+	// First, ActiveConfig
+
+	weight += T::DbWeight::get().reads_writes(1, 1);
 	if let Err(_) = <Pallet<T> as Store>::ActiveConfig::translate(|pre| pre.map(translate)) {
 		// `Err` is returned when the pre-migration type cannot be deserialized. This
 		// cannot happen if the migration runs correctly, i.e. against the expected version.
@@ -205,7 +213,24 @@ minimum_validation_upgrade_delay: pre.chain_availability_period + 10u32.into(),
 		);
 	}
 
-	T::DbWeight::get().reads_writes(1, 1)
+	// Second, PendingConfig -> PendingConfigs
+
+	weight += T::DbWeight::get().reads(2);
+	let current_session_index = crate::shared::Pallet::<T>::session_index();
+	let scheduled_session = crate::shared::Pallet::<T>::scheduled_session();
+	let mut pending_configs = Vec::new();
+
+	for session_index in current_session_index..=scheduled_session {
+		weight += T::DbWeight::get().reads(1);
+		if let Some(pending_config) = <Pallet<T> as Store>::PendingConfig::get(session_index) {
+			pending_configs.push((session_index, translate(pending_config)));
+		}
+	}
+
+	weight += T::DbWeight::get().writes(1);
+	<Pallet<T> as Store>::PendingConfigs::put(&pending_configs);
+
+	weight
 }
 
 #[cfg(test)]
@@ -254,66 +279,111 @@ mod tests {
 			chain_availability_period: 33,
 			..Default::default()
 		};
+		let pending_configs_v1 = vec![
+			(
+				1,
+				v1::HostConfiguration::<primitives::v1::BlockNumber> {
+					n_delay_tranches: 150,
+					..v1.clone()
+				},
+			),
+			(
+				2,
+				v1::HostConfiguration::<primitives::v1::BlockNumber> {
+					max_validators_per_core: Some(33),
+					..v1.clone()
+				},
+			),
+			(
+				3,
+				v1::HostConfiguration::<primitives::v1::BlockNumber> {
+					parathread_retries: 11,
+					..v1.clone()
+				},
+			),
+		];
 
 		new_test_ext(Default::default()).execute_with(|| {
-			// Implant the v1 version in the state.
+			// Implant the v1 data in the state.
 			frame_support::storage::unhashed::put_raw(
 				&configuration::ActiveConfig::<Test>::hashed_key(),
 				&v1.encode(),
 			);
+			for (session_index, pending_config) in &pending_configs_v1 {
+				frame_support::storage::unhashed::put_raw(
+					&configuration::PendingConfig::<Test>::hashed_key_for(session_index),
+					&pending_config.encode(),
+				);
+			}
+
+			// Assume the session index 1.
+			crate::shared::Pallet::<Test>::set_session_index(1);
 
 			migrate_to_v2::<Test>();
 
 			let v2 = configuration::ActiveConfig::<Test>::get();
 
-			// The same motivation as for the migration code. See `migrate_to_v2`.
-			#[rustfmt::skip]
+			assert_correct_translation(v1, v2);
+			let pending_configs_v2 = configuration::PendingConfigs::<Test>::get();
+			assert_eq!(pending_configs_v1.len(), pending_configs_v2.len());
+			for ((session_index_v1, pending_config_v1), (session_index_v2, pending_configs_v2)) in
+				pending_configs_v1.into_iter().zip(pending_configs_v2.into_iter())
 			{
-				assert_eq!(v1.max_code_size                            , v2.max_code_size);
-				assert_eq!(v1.max_head_data_size                       , v2.max_head_data_size);
-				assert_eq!(v1.max_upward_queue_count                   , v2.max_upward_queue_count);
-				assert_eq!(v1.max_upward_queue_size                    , v2.max_upward_queue_size);
-				assert_eq!(v1.max_upward_message_size                  , v2.max_upward_message_size);
-				assert_eq!(v1.max_upward_message_num_per_candidate     , v2.max_upward_message_num_per_candidate);
-				assert_eq!(v1.hrmp_max_message_num_per_candidate       , v2.hrmp_max_message_num_per_candidate);
-				assert_eq!(v1.validation_upgrade_frequency             , v2.validation_upgrade_frequency);
-				assert_eq!(v1.validation_upgrade_delay                 , v2.validation_upgrade_delay);
-				assert_eq!(v1.max_pov_size                             , v2.max_pov_size);
-				assert_eq!(v1.max_downward_message_size                , v2.max_downward_message_size);
-				assert_eq!(v1.ump_service_total_weight                 , v2.ump_service_total_weight);
-				assert_eq!(v1.hrmp_max_parachain_outbound_channels     , v2.hrmp_max_parachain_outbound_channels);
-				assert_eq!(v1.hrmp_max_parathread_outbound_channels    , v2.hrmp_max_parathread_outbound_channels);
-				assert_eq!(v1.hrmp_sender_deposit                      , v2.hrmp_sender_deposit);
-				assert_eq!(v1.hrmp_recipient_deposit                   , v2.hrmp_recipient_deposit);
-				assert_eq!(v1.hrmp_channel_max_capacity                , v2.hrmp_channel_max_capacity);
-				assert_eq!(v1.hrmp_channel_max_total_size              , v2.hrmp_channel_max_total_size);
-				assert_eq!(v1.hrmp_max_parachain_inbound_channels      , v2.hrmp_max_parachain_inbound_channels);
-				assert_eq!(v1.hrmp_max_parathread_inbound_channels     , v2.hrmp_max_parathread_inbound_channels);
-				assert_eq!(v1.hrmp_channel_max_message_size            , v2.hrmp_channel_max_message_size);
-				assert_eq!(v1.code_retention_period                    , v2.code_retention_period);
-				assert_eq!(v1.parathread_cores                         , v2.parathread_cores);
-				assert_eq!(v1.parathread_retries                       , v2.parathread_retries);
-				assert_eq!(v1.group_rotation_frequency                 , v2.group_rotation_frequency);
-				assert_eq!(v1.chain_availability_period                , v2.chain_availability_period);
-				assert_eq!(v1.thread_availability_period               , v2.thread_availability_period);
-				assert_eq!(v1.scheduling_lookahead                     , v2.scheduling_lookahead);
-				assert_eq!(v1.max_validators_per_core                  , v2.max_validators_per_core);
-				assert_eq!(v1.max_validators                           , v2.max_validators);
-				assert_eq!(v1.dispute_period                           , v2.dispute_period);
-				assert_eq!(v1.dispute_post_conclusion_acceptance_period, v2.dispute_post_conclusion_acceptance_period);
-				assert_eq!(v1.dispute_max_spam_slots                   , v2.dispute_max_spam_slots);
-				assert_eq!(v1.dispute_conclusion_by_time_out_period    , v2.dispute_conclusion_by_time_out_period);
-				assert_eq!(v1.no_show_slots                            , v2.no_show_slots);
-				assert_eq!(v1.n_delay_tranches                         , v2.n_delay_tranches);
-				assert_eq!(v1.zeroth_delay_tranche_width               , v2.zeroth_delay_tranche_width);
-				assert_eq!(v1.needed_approvals                         , v2.needed_approvals);
-				assert_eq!(v1.relay_vrf_modulo_samples                 , v2.relay_vrf_modulo_samples);
-				assert_eq!(v1.ump_max_individual_weight                , v2.ump_max_individual_weight);
-
-				assert_eq!(v2.pvf_checking_enabled, false);
-				assert_eq!(v2.pvf_voting_ttl, 2);
-				assert_eq!(v2.minimum_validation_upgrade_delay, 43);
-			}; // ; makes this a statement. `rustfmt::skip` cannot be put on an expression.
+				assert_eq!(session_index_v1, session_index_v2);
+				assert_correct_translation(pending_config_v1, pending_configs_v2);
+			}
 		});
+
+		// The same motivation as for the migration code. See `migrate_to_v2`.
+		#[rustfmt::skip]
+		fn assert_correct_translation(
+			v1: v1::HostConfiguration<primitives::v1::BlockNumber>, 
+			v2: configuration::HostConfiguration<primitives::v1::BlockNumber>
+		) {
+			assert_eq!(v1.max_code_size                            , v2.max_code_size);
+			assert_eq!(v1.max_head_data_size                       , v2.max_head_data_size);
+			assert_eq!(v1.max_upward_queue_count                   , v2.max_upward_queue_count);
+			assert_eq!(v1.max_upward_queue_size                    , v2.max_upward_queue_size);
+			assert_eq!(v1.max_upward_message_size                  , v2.max_upward_message_size);
+			assert_eq!(v1.max_upward_message_num_per_candidate     , v2.max_upward_message_num_per_candidate);
+			assert_eq!(v1.hrmp_max_message_num_per_candidate       , v2.hrmp_max_message_num_per_candidate);
+			assert_eq!(v1.validation_upgrade_frequency             , v2.validation_upgrade_frequency);
+			assert_eq!(v1.validation_upgrade_delay                 , v2.validation_upgrade_delay);
+			assert_eq!(v1.max_pov_size                             , v2.max_pov_size);
+			assert_eq!(v1.max_downward_message_size                , v2.max_downward_message_size);
+			assert_eq!(v1.ump_service_total_weight                 , v2.ump_service_total_weight);
+			assert_eq!(v1.hrmp_max_parachain_outbound_channels     , v2.hrmp_max_parachain_outbound_channels);
+			assert_eq!(v1.hrmp_max_parathread_outbound_channels    , v2.hrmp_max_parathread_outbound_channels);
+			assert_eq!(v1.hrmp_sender_deposit                      , v2.hrmp_sender_deposit);
+			assert_eq!(v1.hrmp_recipient_deposit                   , v2.hrmp_recipient_deposit);
+			assert_eq!(v1.hrmp_channel_max_capacity                , v2.hrmp_channel_max_capacity);
+			assert_eq!(v1.hrmp_channel_max_total_size              , v2.hrmp_channel_max_total_size);
+			assert_eq!(v1.hrmp_max_parachain_inbound_channels      , v2.hrmp_max_parachain_inbound_channels);
+			assert_eq!(v1.hrmp_max_parathread_inbound_channels     , v2.hrmp_max_parathread_inbound_channels);
+			assert_eq!(v1.hrmp_channel_max_message_size            , v2.hrmp_channel_max_message_size);
+			assert_eq!(v1.code_retention_period                    , v2.code_retention_period);
+			assert_eq!(v1.parathread_cores                         , v2.parathread_cores);
+			assert_eq!(v1.parathread_retries                       , v2.parathread_retries);
+			assert_eq!(v1.group_rotation_frequency                 , v2.group_rotation_frequency);
+			assert_eq!(v1.chain_availability_period                , v2.chain_availability_period);
+			assert_eq!(v1.thread_availability_period               , v2.thread_availability_period);
+			assert_eq!(v1.scheduling_lookahead                     , v2.scheduling_lookahead);
+			assert_eq!(v1.max_validators_per_core                  , v2.max_validators_per_core);
+			assert_eq!(v1.max_validators                           , v2.max_validators);
+			assert_eq!(v1.dispute_period                           , v2.dispute_period);
+			assert_eq!(v1.dispute_post_conclusion_acceptance_period, v2.dispute_post_conclusion_acceptance_period);
+			assert_eq!(v1.dispute_max_spam_slots                   , v2.dispute_max_spam_slots);
+			assert_eq!(v1.dispute_conclusion_by_time_out_period    , v2.dispute_conclusion_by_time_out_period);
+			assert_eq!(v1.no_show_slots                            , v2.no_show_slots);
+			assert_eq!(v1.n_delay_tranches                         , v2.n_delay_tranches);
+			assert_eq!(v1.zeroth_delay_tranche_width               , v2.zeroth_delay_tranche_width);
+			assert_eq!(v1.needed_approvals                         , v2.needed_approvals);
+			assert_eq!(v1.relay_vrf_modulo_samples                 , v2.relay_vrf_modulo_samples);
+			assert_eq!(v1.ump_max_individual_weight                , v2.ump_max_individual_weight);
+
+			assert_eq!(v2.pvf_checking_enabled, false);
+			assert_eq!(v2.pvf_voting_ttl, 2);
+			assert_eq!(v2.minimum_validation_upgrade_delay, 43);
+		}
 	}
 }
diff --git a/runtime/polkadot/src/weights/runtime_parachains_configuration.rs b/runtime/polkadot/src/weights/runtime_parachains_configuration.rs
index ad84a780a4d0..c36dbc7544b5 100644
--- a/runtime/polkadot/src/weights/runtime_parachains_configuration.rs
+++ b/runtime/polkadot/src/weights/runtime_parachains_configuration.rs
@@ -16,7 +16,7 @@
 //! Autogenerated weights for `runtime_parachains::configuration`
 //!
 //! THIS FILE WAS AUTO-GENERATED USING THE SUBSTRATE BENCHMARK CLI VERSION 4.0.0-dev
-//! DATE: 2021-10-09, STEPS: `50`, REPEAT: 20, LOW RANGE: `[]`, HIGH RANGE: `[]`
+//! DATE: 2021-12-16, STEPS: `50`, REPEAT: 20, LOW RANGE: `[]`, HIGH RANGE: `[]`
 //! EXECUTION: Some(Wasm), WASM-EXECUTION: Compiled, CHAIN: Some("polkadot-dev"), DB CACHE: 128
 
 // Executed Command:
@@ -33,7 +33,6 @@
 // --header=./file_header.txt
 // --output=./runtime/polkadot/src/weights/runtime_parachains_configuration.rs
 
-
 #![cfg_attr(rustfmt, rustfmt_skip)]
 #![allow(unused_parens)]
 #![allow(unused_imports)]
@@ -44,35 +43,35 @@ use sp_std::marker::PhantomData;
 /// Weight functions for `runtime_parachains::configuration`.
 pub struct WeightInfo<T>(PhantomData<T>);
 impl<T: frame_system::Config> runtime_parachains::configuration::WeightInfo for WeightInfo<T> {
-	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: Configuration ActiveConfig (r:1 w:0)
+	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
 	fn set_config_with_block_number() -> Weight {
-		(12_506_000 as Weight)
+		(8_144_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(3 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
-	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: Configuration ActiveConfig (r:1 w:0)
+	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
 	fn set_config_with_u32() -> Weight {
-		(12_550_000 as Weight)
+		(8_100_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(3 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
-	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: Configuration ActiveConfig (r:1 w:0)
+	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
 	fn set_config_with_option_u32() -> Weight {
-		(12_521_000 as Weight)
+		(8_146_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(3 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
-	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: Configuration ActiveConfig (r:1 w:0)
+	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
 	fn set_config_with_weight() -> Weight {
-		(12_867_000 as Weight)
+		(8_716_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(3 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
@@ -80,11 +79,11 @@ impl<T: frame_system::Config> runtime_parachains::configuration::WeightInfo for
 	fn set_hrmp_open_request_ttl() -> Weight {
 		(2_000_000_000_000 as Weight)
 	}
-	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: Configuration ActiveConfig (r:1 w:0)
+	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
 	fn set_config_with_balance() -> Weight {
-		(12_852_000 as Weight)
+		(8_735_000 as Weight)
 			.saturating_add(T::DbWeight::get().reads(3 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
diff --git a/runtime/westend/src/weights/runtime_parachains_configuration.rs b/runtime/westend/src/weights/runtime_parachains_configuration.rs
index 6c1753e7c3b3..976fcd025b57 100644
--- a/runtime/westend/src/weights/runtime_parachains_configuration.rs
+++ b/runtime/westend/src/weights/runtime_parachains_configuration.rs
@@ -16,7 +16,7 @@
 //! Autogenerated weights for `runtime_parachains::configuration`
 //!
 //! THIS FILE WAS AUTO-GENERATED USING THE SUBSTRATE BENCHMARK CLI VERSION 4.0.0-dev
-//! DATE: 2021-09-17, STEPS: `50`, REPEAT: 20, LOW RANGE: `[]`, HIGH RANGE: `[]`
+//! DATE: 2021-12-16, STEPS: `50`, REPEAT: 20, LOW RANGE: `[]`, HIGH RANGE: `[]`
 //! EXECUTION: Some(Wasm), WASM-EXECUTION: Compiled, CHAIN: Some("westend-dev"), DB CACHE: 128
 
 // Executed Command:
@@ -33,7 +33,6 @@
 // --header=./file_header.txt
 // --output=./runtime/westend/src/weights/runtime_parachains_configuration.rs
 
-
 #![cfg_attr(rustfmt, rustfmt_skip)]
 #![allow(unused_parens)]
 #![allow(unused_imports)]
@@ -44,48 +43,43 @@ use sp_std::marker::PhantomData;
 /// Weight functions for `runtime_parachains::configuration`.
 pub struct WeightInfo<T>(PhantomData<T>);
 impl<T: frame_system::Config> runtime_parachains::configuration::WeightInfo for WeightInfo<T> {
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
-	// Storage: Configuration ActiveConfig (r:1 w:0)
 	fn set_config_with_block_number() -> Weight {
-		(12_795_000 as Weight)
-			.saturating_add(T::DbWeight::get().reads(3 as Weight))
+		(7_735_000 as Weight)
+			.saturating_add(T::DbWeight::get().reads(2 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
-	// Storage: Configuration ActiveConfig (r:1 w:0)
 	fn set_config_with_u32() -> Weight {
-		(12_758_000 as Weight)
-			.saturating_add(T::DbWeight::get().reads(3 as Weight))
+		(7_824_000 as Weight)
+			.saturating_add(T::DbWeight::get().reads(2 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
-	// Storage: Configuration ActiveConfig (r:1 w:0)
 	fn set_config_with_option_u32() -> Weight {
-		(12_861_000 as Weight)
-			.saturating_add(T::DbWeight::get().reads(3 as Weight))
+		(8_121_000 as Weight)
+			.saturating_add(T::DbWeight::get().reads(2 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
-	// Storage: Configuration ActiveConfig (r:1 w:0)
 	fn set_config_with_weight() -> Weight {
-		(12_854_000 as Weight)
-			.saturating_add(T::DbWeight::get().reads(3 as Weight))
+		(8_011_000 as Weight)
+			.saturating_add(T::DbWeight::get().reads(2 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
 	// Storage: Benchmark Override (r:0 w:0)
 	fn set_hrmp_open_request_ttl() -> Weight {
 		(2_000_000_000_000 as Weight)
 	}
+	// Storage: Configuration PendingConfigs (r:1 w:1)
 	// Storage: ParasShared CurrentSessionIndex (r:1 w:0)
-	// Storage: Configuration PendingConfig (r:1 w:1)
-	// Storage: Configuration ActiveConfig (r:1 w:0)
 	fn set_config_with_balance() -> Weight {
-		(12_838_000 as Weight)
-			.saturating_add(T::DbWeight::get().reads(3 as Weight))
+		(7_954_000 as Weight)
+			.saturating_add(T::DbWeight::get().reads(2 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
 }