diff --git a/pallets/collator-assignment/src/lib.rs b/pallets/collator-assignment/src/lib.rs
index f2eca9f31..f8f29d783 100644
--- a/pallets/collator-assignment/src/lib.rs
+++ b/pallets/collator-assignment/src/lib.rs
@@ -45,6 +45,7 @@ pub use pallet::*;
 use {
     crate::weights::WeightInfo,
     frame_support::pallet_prelude::*,
+    frame_system::pallet_prelude::BlockNumberFor,
     rand::{seq::SliceRandom, SeedableRng},
     rand_chacha::ChaCha20Rng,
     sp_runtime::{
@@ -93,6 +94,7 @@ pub mod pallet {
         type HostConfiguration: GetHostConfiguration<Self::SessionIndex>;
         type ContainerChains: GetSessionContainerChains<Self::SessionIndex>;
         type ShouldRotateAllCollators: ShouldRotateAllCollators<Self::SessionIndex>;
+        type GetRandomnessForNextBlock: GetRandomnessForNextBlock<BlockNumberFor<Self>>;
         /// The weight information of this pallet.
         type WeightInfo: WeightInfo;
     }
@@ -124,6 +126,13 @@ pub mod pallet {
     pub(crate) type PendingCollatorContainerChain<T: Config> =
         StorageValue<_, Option<AssignedCollators<T::AccountId>>, ValueQuery>;
 
+    /// Randomness from previous block. Used to shuffle collators on session change.
+    /// Should only be set on the last block of each session and should be killed on the on_initialize of the next block.
+    /// The default value of [0; 32] disables randomness in the pallet.
+    #[pallet::storage]
+    #[pallet::getter(fn randomness)]
+    pub(crate) type Randomness<T: Config> = StorageValue<_, [u8; 32], ValueQuery>;
+
     #[pallet::call]
     impl<T: Config> Pallet<T> {}
 
@@ -371,9 +380,9 @@ pub mod pallet {
 
         pub fn initializer_on_new_session(
             session_index: &T::SessionIndex,
-            random_seed: [u8; 32],
             collators: Vec<T::AccountId>,
         ) -> SessionChangeOutcome<T> {
+            let random_seed = Randomness::<T>::take();
             let num_collators = collators.len();
             let assigned_collators = Self::assign_collators(session_index, random_seed, collators);
             let num_parachains = assigned_collators.next_assignment.container_chains.len();
@@ -406,6 +415,28 @@ pub mod pallet {
             CollatorContainerChain::<T>::put(assigned_collators);
         }
     }
+
+    #[pallet::hooks]
+    impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
+        fn on_initialize(n: BlockNumberFor<T>) -> Weight {
+            let mut weight = Weight::zero();
+
+            // Account reads and writes for on_finalize
+            if T::GetRandomnessForNextBlock::should_end_session(n.saturating_add(One::one())) {
+                weight += T::DbWeight::get().reads_writes(1, 1);
+            }
+
+            weight
+        }
+
+        fn on_finalize(n: BlockNumberFor<T>) {
+            // If the next block is a session change, read randomness and store in pallet storage
+            if T::GetRandomnessForNextBlock::should_end_session(n.saturating_add(One::one())) {
+                let random_seed = T::GetRandomnessForNextBlock::get_randomness();
+                Randomness::<T>::put(random_seed);
+            }
+        }
+    }
 }
 
 pub struct RotateCollatorsEveryNSessions<Period>(PhantomData<Period>);
@@ -418,3 +449,8 @@ where
         session_index % Period::get() == 0
     }
 }
+
+pub trait GetRandomnessForNextBlock<BlockNumber> {
+    fn should_end_session(block_number: BlockNumber) -> bool;
+    fn get_randomness() -> [u8; 32];
+}
diff --git a/pallets/collator-assignment/src/mock.rs b/pallets/collator-assignment/src/mock.rs
index 9aac5a0a9..b6c9b721f 100644
--- a/pallets/collator-assignment/src/mock.rs
+++ b/pallets/collator-assignment/src/mock.rs
@@ -14,8 +14,13 @@
 // You should have received a copy of the GNU General Public License
 // along with Tanssi.  If not, see <http://www.gnu.org/licenses/>
 
+use frame_support::traits::Hooks;
+
 use {
-    crate::{self as pallet_collator_assignment, RotateCollatorsEveryNSessions},
+    crate::{
+        self as pallet_collator_assignment, GetRandomnessForNextBlock,
+        RotateCollatorsEveryNSessions,
+    },
     frame_support::{
         parameter_types,
         traits::{ConstU16, ConstU64},
@@ -161,6 +166,18 @@ impl tp_traits::GetSessionContainerChains<u32> for ContainerChainsGetter {
     }
 }
 
+pub struct MockGetRandomnessForNextBlock;
+
+impl GetRandomnessForNextBlock<u64> for MockGetRandomnessForNextBlock {
+    fn should_end_session(n: u64) -> bool {
+        n % 5 == 0
+    }
+
+    fn get_randomness() -> [u8; 32] {
+        MockData::mock().random_seed
+    }
+}
+
 parameter_types! {
     pub const CollatorRotationSessionPeriod: u32 = 5;
 }
@@ -171,6 +188,7 @@ impl pallet_collator_assignment::Config for Test {
     type HostConfiguration = HostConfigurationGetter;
     type ContainerChains = ContainerChainsGetter;
     type ShouldRotateAllCollators = RotateCollatorsEveryNSessions<CollatorRotationSessionPeriod>;
+    type GetRandomnessForNextBlock = MockGetRandomnessForNextBlock;
     type WeightInfo = ();
 }
 
@@ -193,15 +211,16 @@ pub fn run_to_block(n: u64) {
     for x in (old_block_number + 1)..=n {
         System::reset_events();
         System::set_block_number(x);
-        let randomness = MockData::mock().random_seed;
+        CollatorAssignment::on_initialize(x);
 
         if x % session_len == 1 {
             let session_index = (x / session_len) as u32;
             CollatorAssignment::initializer_on_new_session(
                 &session_index,
-                randomness,
                 CollatorsGetter::collators(session_index),
             );
         }
+
+        CollatorAssignment::on_finalize(x);
     }
 }
diff --git a/runtime/dancebox/src/lib.rs b/runtime/dancebox/src/lib.rs
index 14a50f513..54f3f9b88 100644
--- a/runtime/dancebox/src/lib.rs
+++ b/runtime/dancebox/src/lib.rs
@@ -63,7 +63,7 @@ use {
         EnsureRoot,
     },
     nimbus_primitives::NimbusId,
-    pallet_collator_assignment::RotateCollatorsEveryNSessions,
+    pallet_collator_assignment::{GetRandomnessForNextBlock, RotateCollatorsEveryNSessions},
     pallet_pooled_staking::traits::{IsCandidateEligible, Timer},
     pallet_registrar_runtime_api::ContainerChainGenesisData,
     pallet_session::{SessionManager, ShouldEndSession},
@@ -507,26 +507,6 @@ impl pallet_initializer::ApplyNewSession<Runtime> for OwnApplySession {
         all_validators: Vec<(AccountId, NimbusId)>,
         queued: Vec<(AccountId, NimbusId)>,
     ) {
-        let random_seed = if session_index != 0 {
-            if let Some(random_hash) =
-                BabeCurrentBlockRandomnessGetter::get_block_randomness_mixed(b"CollatorAssignment")
-            {
-                // Return random_hash as a [u8; 32] instead of a Hash
-                let mut buf = [0u8; 32];
-                let len = sp_std::cmp::min(32, random_hash.as_ref().len());
-                buf[..len].copy_from_slice(&random_hash.as_ref()[..len]);
-
-                buf
-            } else {
-                // If there is no randomness (e.g when running in dev mode), return [0; 32]
-                // TODO: smoke test to ensure this never happens in a live network
-                [0; 32]
-            }
-        } else {
-            // In session 0 (genesis) there is randomness
-            [0; 32]
-        };
-
         // We first initialize Configuration
         Configuration::initializer_on_new_session(&session_index);
         // Next: Registrar
@@ -537,11 +517,8 @@ impl pallet_initializer::ApplyNewSession<Runtime> for OwnApplySession {
         let next_collators = queued.iter().map(|(k, _)| k.clone()).collect();
 
         // Next: CollatorAssignment
-        let assignments = CollatorAssignment::initializer_on_new_session(
-            &session_index,
-            random_seed,
-            next_collators,
-        );
+        let assignments =
+            CollatorAssignment::initializer_on_new_session(&session_index, next_collators);
 
         let queued_id_to_nimbus_map = queued.iter().cloned().collect();
         AuthorityAssignment::initializer_on_new_session(
@@ -640,6 +617,39 @@ impl Get<u32> for ConfigurationCollatorRotationSessionPeriod {
     }
 }
 
+pub struct BabeGetRandomnessForNextBlock;
+
+impl GetRandomnessForNextBlock<u32> for BabeGetRandomnessForNextBlock {
+    fn should_end_session(n: u32) -> bool {
+        <Runtime as pallet_session::Config>::ShouldEndSession::should_end_session(n)
+    }
+
+    fn get_randomness() -> [u8; 32] {
+        let block_number = System::block_number();
+        let random_seed = if block_number != 0 {
+            if let Some(random_hash) =
+                BabeCurrentBlockRandomnessGetter::get_block_randomness_mixed(b"CollatorAssignment")
+            {
+                // Return random_hash as a [u8; 32] instead of a Hash
+                let mut buf = [0u8; 32];
+                let len = sp_std::cmp::min(32, random_hash.as_ref().len());
+                buf[..len].copy_from_slice(&random_hash.as_ref()[..len]);
+
+                buf
+            } else {
+                // If there is no randomness (e.g when running in dev mode), return [0; 32]
+                // TODO: smoke test to ensure this never happens in a live network
+                [0; 32]
+            }
+        } else {
+            // In block 0 (genesis) there is randomness
+            [0; 32]
+        };
+
+        random_seed
+    }
+}
+
 impl pallet_collator_assignment::Config for Runtime {
     type RuntimeEvent = RuntimeEvent;
     type HostConfiguration = Configuration;
@@ -647,6 +657,7 @@ impl pallet_collator_assignment::Config for Runtime {
     type SessionIndex = u32;
     type ShouldRotateAllCollators =
         RotateCollatorsEveryNSessions<ConfigurationCollatorRotationSessionPeriod>;
+    type GetRandomnessForNextBlock = BabeGetRandomnessForNextBlock;
     type WeightInfo = pallet_collator_assignment::weights::SubstrateWeight<Runtime>;
 }
 
diff --git a/runtime/dancebox/tests/common/mod.rs b/runtime/dancebox/tests/common/mod.rs
index 768078711..79b2428ea 100644
--- a/runtime/dancebox/tests/common/mod.rs
+++ b/runtime/dancebox/tests/common/mod.rs
@@ -17,7 +17,9 @@
 use {
     cumulus_primitives_core::{ParaId, PersistedValidationData},
     cumulus_primitives_parachain_inherent::ParachainInherentData,
-    dancebox_runtime::{AuthorInherent, AuthorityAssignment, MaxLengthTokenSymbol},
+    dancebox_runtime::{
+        AuthorInherent, AuthorityAssignment, CollatorAssignment, MaxLengthTokenSymbol,
+    },
     frame_support::{
         assert_ok,
         traits::{OnFinalize, OnInitialize},
@@ -78,16 +80,18 @@ pub fn run_to_block(n: u32) {
         );
 
         // Initialize the new block
-        Session::on_initialize(System::block_number());
+        CollatorAssignment::on_initialize(System::block_number());
         Initializer::on_initialize(System::block_number());
+        Session::on_initialize(System::block_number());
         AuthorInherent::on_initialize(System::block_number());
 
         pallet_author_inherent::Pallet::<Runtime>::kick_off_authorship_validation(None.into())
             .expect("author inherent to dispatch correctly");
 
         // Finalize the block
-        Session::on_finalize(System::block_number());
+        CollatorAssignment::on_finalize(System::block_number());
         Initializer::on_finalize(System::block_number());
+        Session::on_finalize(System::block_number());
         AuthorInherent::on_finalize(System::block_number());
     }
 }