diff --git a/crates/pallet-domains/src/tests.rs b/crates/pallet-domains/src/tests.rs
index 748d3b62265..1b80d340f64 100644
--- a/crates/pallet-domains/src/tests.rs
+++ b/crates/pallet-domains/src/tests.rs
@@ -470,7 +470,7 @@ fn submit_fraud_proof_should_work() {
             domain_id,
             bad_receipt_hash: Hash::random(),
             parent_number: 99,
-            parent_hash: block_hashes[98],
+            primary_parent_hash: block_hashes[98],
             pre_state_root: H256::random(),
             post_state_root: H256::random(),
             proof: StorageProof::empty(),
diff --git a/crates/pallet-receipts/src/lib.rs b/crates/pallet-receipts/src/lib.rs
index f8b2b5bfb81..b0a2d6f3fc7 100644
--- a/crates/pallet-receipts/src/lib.rs
+++ b/crates/pallet-receipts/src/lib.rs
@@ -359,11 +359,12 @@ impl<T: Config> Pallet<T> {
             FraudProofError::ExecutionReceiptInFuture
         );
 
-        let parent_hash = T::Hash::decode(&mut fraud_proof.parent_hash.encode().as_slice())
-            .map_err(|_| FraudProofError::WrongHashType)?;
+        let primary_parent_hash =
+            T::Hash::decode(&mut fraud_proof.primary_parent_hash.encode().as_slice())
+                .map_err(|_| FraudProofError::WrongHashType)?;
         let parent_number: T::BlockNumber = fraud_proof.parent_number.into();
         ensure!(
-            Self::primary_hash(fraud_proof.domain_id, parent_number) == Some(parent_hash),
+            Self::primary_hash(fraud_proof.domain_id, parent_number) == Some(primary_parent_hash),
             FraudProofError::UnknownBlock
         );
 
diff --git a/crates/sp-domains/src/fraud_proof.rs b/crates/sp-domains/src/fraud_proof.rs
index ccd567d57a1..3ab629432b0 100644
--- a/crates/sp-domains/src/fraud_proof.rs
+++ b/crates/sp-domains/src/fraud_proof.rs
@@ -9,11 +9,12 @@ use sp_trie::StorageProof;
 use subspace_core_primitives::BlockNumber;
 use subspace_runtime_primitives::AccountId;
 
-/// A phase of a block's execution.
+/// A phase of a block's execution, carrying necessary information needed for verifying the
+/// invalid state transition proof.
 #[derive(Debug, Decode, Encode, TypeInfo, PartialEq, Eq, Clone)]
 pub enum ExecutionPhase {
     /// Executes the `initialize_block` hook.
-    InitializeBlock,
+    InitializeBlock { domain_parent_hash: H256 },
     /// Executes some extrinsic.
     ApplyExtrinsic(u32),
     /// Executes the `finalize_block` hook.
@@ -26,7 +27,7 @@ impl ExecutionPhase {
         match self {
             // TODO: Replace `DomainCoreApi_initialize_block_with_post_state_root` with `Core_initalize_block`
             // Should be a same issue with https://github.com/paritytech/substrate/pull/10922#issuecomment-1068997467
-            Self::InitializeBlock => "DomainCoreApi_initialize_block_with_post_state_root",
+            Self::InitializeBlock { .. } => "DomainCoreApi_initialize_block_with_post_state_root",
             Self::ApplyExtrinsic(_) => "BlockBuilder_apply_extrinsic",
             Self::FinalizeBlock { .. } => "BlockBuilder_finalize_block",
         }
@@ -39,7 +40,7 @@ impl ExecutionPhase {
     /// result of execution reported in [`FraudProof`] is expected or not.
     pub fn verifying_method(&self) -> &'static str {
         match self {
-            Self::InitializeBlock => "DomainCoreApi_initialize_block_with_post_state_root",
+            Self::InitializeBlock { .. } => "DomainCoreApi_initialize_block_with_post_state_root",
             Self::ApplyExtrinsic(_) => "DomainCoreApi_apply_extrinsic_with_post_state_root",
             Self::FinalizeBlock { .. } => "BlockBuilder_finalize_block",
         }
@@ -51,7 +52,7 @@ impl ExecutionPhase {
         execution_result: Vec<u8>,
     ) -> Result<Header::Hash, VerificationError> {
         match self {
-            Self::InitializeBlock | Self::ApplyExtrinsic(_) => {
+            Self::InitializeBlock { .. } | Self::ApplyExtrinsic(_) => {
                 let encoded_storage_root = Vec::<u8>::decode(&mut execution_result.as_slice())
                     .map_err(VerificationError::InitializeBlockOrApplyExtrinsicDecode)?;
                 Header::Hash::decode(&mut encoded_storage_root.as_slice())
@@ -158,10 +159,11 @@ pub struct InvalidStateTransitionProof {
     pub bad_receipt_hash: H256,
     /// Parent number.
     pub parent_number: BlockNumber,
-    /// Parent hash of the block at which the invalid execution occurred.
+    /// Hash of the primary block corresponding to `parent_number`.
     ///
-    /// Runtime code for this block's execution is retrieved on top of the parent block.
-    pub parent_hash: H256,
+    /// Runtime code for the execution of the domain block that is being challenged
+    /// is retrieved on top of the primary parent block from the primary chain.
+    pub primary_parent_hash: H256,
     /// State root before the fraudulent transaction.
     pub pre_state_root: H256,
     /// State root after the fraudulent transaction.
diff --git a/crates/subspace-fraud-proof/src/invalid_state_transition_proof.rs b/crates/subspace-fraud-proof/src/invalid_state_transition_proof.rs
index d01ee2459f6..e628badda64 100644
--- a/crates/subspace-fraud-proof/src/invalid_state_transition_proof.rs
+++ b/crates/subspace-fraud-proof/src/invalid_state_transition_proof.rs
@@ -259,22 +259,23 @@ where
     ) -> Result<(), VerificationError> {
         let InvalidStateTransitionProof {
             domain_id,
-            bad_receipt_hash,
             parent_number,
-            parent_hash,
+            bad_receipt_hash,
             pre_state_root,
             execution_phase,
             ..
         } = invalid_state_transition_proof;
 
         let pre_state_root_onchain = match execution_phase {
-            ExecutionPhase::InitializeBlock => self.client.runtime_api().state_root(
-                self.client.info().best_hash,
-                *domain_id,
-                NumberFor::<Block>::from(*parent_number),
-                Block::Hash::decode(&mut parent_hash.encode().as_slice())
-                    .expect("Block Hash must be H256; qed"),
-            )?,
+            ExecutionPhase::InitializeBlock { domain_parent_hash } => {
+                self.client.runtime_api().state_root(
+                    self.client.info().best_hash,
+                    *domain_id,
+                    NumberFor::<Block>::from(*parent_number),
+                    Block::Hash::decode(&mut domain_parent_hash.encode().as_slice())
+                        .expect("Block Hash must be H256; qed"),
+                )?
+            }
             ExecutionPhase::ApplyExtrinsic(trace_index_of_pre_state_root)
             | ExecutionPhase::FinalizeBlock {
                 total_extrinsics: trace_index_of_pre_state_root,
@@ -319,7 +320,7 @@ where
         )?;
 
         let post_state_root_onchain = match execution_phase {
-            ExecutionPhase::InitializeBlock => trace
+            ExecutionPhase::InitializeBlock { .. } => trace
                 .get(0)
                 .ok_or(VerificationError::PostStateRootNotFound)?,
             ExecutionPhase::ApplyExtrinsic(trace_index_of_post_state_root)
@@ -396,7 +397,7 @@ where
 
         let InvalidStateTransitionProof {
             domain_id,
-            parent_hash,
+            primary_parent_hash,
             pre_state_root,
             post_state_root,
             proof,
@@ -404,7 +405,7 @@ where
             ..
         } = invalid_state_transition_proof;
 
-        let at = PBlock::Hash::decode(&mut parent_hash.encode().as_slice())
+        let at = PBlock::Hash::decode(&mut primary_parent_hash.encode().as_slice())
             .expect("Block Hash must be H256; qed");
         let system_wasm_bundle = self
             .client
diff --git a/crates/subspace-fraud-proof/src/tests.rs b/crates/subspace-fraud-proof/src/tests.rs
index 1e2610f9284..3b454c90f5e 100644
--- a/crates/subspace-fraud-proof/src/tests.rs
+++ b/crates/subspace-fraud-proof/src/tests.rs
@@ -159,7 +159,9 @@ async fn execution_proof_creation_and_verification_should_work() {
         parent_header.hash(),
         Default::default(),
     );
-    let execution_phase = ExecutionPhase::InitializeBlock;
+    let execution_phase = ExecutionPhase::InitializeBlock {
+        domain_parent_hash: parent_header.hash(),
+    };
     let initialize_block_call_data = new_header.encode();
 
     let prover = ExecutionProver::new(
@@ -208,7 +210,7 @@ async fn execution_proof_creation_and_verification_should_work() {
         domain_id: TEST_DOMAIN_ID,
         bad_receipt_hash: Hash::random(),
         parent_number: parent_number_alice,
-        parent_hash: parent_hash_alice,
+        primary_parent_hash: parent_hash_alice,
         pre_state_root: *parent_header.state_root(),
         post_state_root: intermediate_roots[0].into(),
         proof: storage_proof,
@@ -266,7 +268,7 @@ async fn execution_proof_creation_and_verification_should_work() {
             domain_id: TEST_DOMAIN_ID,
             bad_receipt_hash: Hash::random(),
             parent_number: parent_number_alice,
-            parent_hash: parent_hash_alice,
+            primary_parent_hash: parent_hash_alice,
             pre_state_root: intermediate_roots[target_extrinsic_index].into(),
             post_state_root: intermediate_roots[target_extrinsic_index + 1].into(),
             proof: storage_proof,
@@ -320,7 +322,7 @@ async fn execution_proof_creation_and_verification_should_work() {
         domain_id: TEST_DOMAIN_ID,
         bad_receipt_hash: Hash::random(),
         parent_number: parent_number_alice,
-        parent_hash: parent_hash_alice,
+        primary_parent_hash: parent_hash_alice,
         pre_state_root: intermediate_roots.last().unwrap().into(),
         post_state_root: post_execution_root,
         proof: storage_proof,
@@ -498,7 +500,7 @@ async fn invalid_execution_proof_should_not_work() {
         domain_id: TEST_DOMAIN_ID,
         bad_receipt_hash: Hash::random(),
         parent_number: parent_number_alice,
-        parent_hash: parent_hash_alice,
+        primary_parent_hash: parent_hash_alice,
         pre_state_root: post_delta_root0,
         post_state_root: post_delta_root1,
         proof: proof1,
@@ -512,7 +514,7 @@ async fn invalid_execution_proof_should_not_work() {
         domain_id: TEST_DOMAIN_ID,
         bad_receipt_hash: Hash::random(),
         parent_number: parent_number_alice,
-        parent_hash: parent_hash_alice,
+        primary_parent_hash: parent_hash_alice,
         pre_state_root: post_delta_root0,
         post_state_root: post_delta_root1,
         proof: proof0.clone(),
@@ -526,7 +528,7 @@ async fn invalid_execution_proof_should_not_work() {
         domain_id: TEST_DOMAIN_ID,
         bad_receipt_hash: Hash::random(),
         parent_number: parent_number_alice,
-        parent_hash: parent_hash_alice,
+        primary_parent_hash: parent_hash_alice,
         pre_state_root: post_delta_root0,
         post_state_root: post_delta_root1,
         proof: proof0,
diff --git a/domains/client/domain-executor/src/core_executor.rs b/domains/client/domain-executor/src/core_executor.rs
index c973906bac2..b515865c335 100644
--- a/domains/client/domain-executor/src/core_executor.rs
+++ b/domains/client/domain-executor/src/core_executor.rs
@@ -31,7 +31,7 @@ pub struct Executor<Block, SBlock, PBlock, Client, SClient, PClient, Transaction
     spawner: Box<dyn SpawnNamed + Send + Sync>,
     transaction_pool: Arc<TransactionPool>,
     backend: Arc<Backend>,
-    fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, Backend, E>,
+    fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, PClient, Backend, E>,
     _phantom_data: PhantomData<(SBlock, SClient)>,
 }
 
@@ -133,6 +133,7 @@ where
 
         let fraud_proof_generator = FraudProofGenerator::new(
             params.client.clone(),
+            params.primary_chain_client.clone(),
             params.spawner.clone(),
             params.backend.clone(),
             params.code_executor,
@@ -183,7 +184,9 @@ where
         })
     }
 
-    pub fn fraud_proof_generator(&self) -> FraudProofGenerator<Block, PBlock, Client, Backend, E> {
+    pub fn fraud_proof_generator(
+        &self,
+    ) -> FraudProofGenerator<Block, PBlock, Client, PClient, Backend, E> {
         self.fraud_proof_generator.clone()
     }
 }
diff --git a/domains/client/domain-executor/src/core_gossip_message_validator.rs b/domains/client/domain-executor/src/core_gossip_message_validator.rs
index 7dfd9f160bb..a4a77be051e 100644
--- a/domains/client/domain-executor/src/core_gossip_message_validator.rs
+++ b/domains/client/domain-executor/src/core_gossip_message_validator.rs
@@ -22,6 +22,7 @@ pub struct CoreGossipMessageValidator<
     PBlock,
     Client,
     SClient,
+    PClient,
     TransactionPool,
     Backend,
     E,
@@ -34,17 +35,19 @@ pub struct CoreGossipMessageValidator<
     parent_chain: ParentChain,
     client: Arc<Client>,
     transaction_pool: Arc<TransactionPool>,
-    gossip_message_validator: GossipMessageValidator<Block, PBlock, Client, Backend, E>,
-    _phantom_data: PhantomData<(SBlock, SClient)>,
+    gossip_message_validator: GossipMessageValidator<Block, PBlock, Client, PClient, Backend, E>,
+    _phantom_data: PhantomData<(SBlock, SClient, PClient)>,
 }
 
-impl<Block, SBlock, PBlock, Client, SClient, TransactionPool, Backend, E, ParentChain> Clone
+impl<Block, SBlock, PBlock, Client, SClient, PClient, TransactionPool, Backend, E, ParentChain>
+    Clone
     for CoreGossipMessageValidator<
         Block,
         SBlock,
         PBlock,
         Client,
         SClient,
+        PClient,
         TransactionPool,
         Backend,
         E,
@@ -67,13 +70,14 @@ where
     }
 }
 
-impl<Block, SBlock, PBlock, Client, SClient, TransactionPool, Backend, E, ParentChain>
+impl<Block, SBlock, PBlock, Client, SClient, PClient, TransactionPool, Backend, E, ParentChain>
     CoreGossipMessageValidator<
         Block,
         SBlock,
         PBlock,
         Client,
         SClient,
+        PClient,
         TransactionPool,
         Backend,
         E,
@@ -93,6 +97,7 @@ where
         + sp_api::ApiExt<Block, StateBackend = StateBackendFor<Backend, Block>>,
     SClient: HeaderBackend<SBlock> + ProvideRuntimeApi<SBlock> + 'static,
     SClient::Api: SystemDomainApi<SBlock, NumberFor<PBlock>, PBlock::Hash>,
+    PClient: HeaderBackend<PBlock> + 'static,
     Backend: sc_client_api::Backend<Block> + 'static,
     TransactionFor<Backend, Block>: sp_trie::HashDBT<HashFor<Block>, sp_trie::DBValue>,
     TransactionPool: sc_transaction_pool_api::TransactionPool<Block = Block> + 'static,
@@ -104,7 +109,7 @@ where
         client: Arc<Client>,
         spawner: Box<dyn SpawnNamed + Send + Sync>,
         transaction_pool: Arc<TransactionPool>,
-        fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, Backend, E>,
+        fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, PClient, Backend, E>,
     ) -> Self {
         let gossip_message_validator =
             GossipMessageValidator::new(client.clone(), spawner, fraud_proof_generator);
@@ -118,7 +123,7 @@ where
     }
 }
 
-impl<Block, SBlock, PBlock, Client, SClient, TransactionPool, Backend, E, ParentChain>
+impl<Block, SBlock, PBlock, Client, SClient, PClient, TransactionPool, Backend, E, ParentChain>
     GossipMessageHandler<PBlock, Block>
     for CoreGossipMessageValidator<
         Block,
@@ -126,6 +131,7 @@ impl<Block, SBlock, PBlock, Client, SClient, TransactionPool, Backend, E, Parent
         PBlock,
         Client,
         SClient,
+        PClient,
         TransactionPool,
         Backend,
         E,
@@ -145,6 +151,7 @@ where
         + sp_api::ApiExt<Block, StateBackend = StateBackendFor<Backend, Block>>,
     SClient: HeaderBackend<SBlock> + ProvideRuntimeApi<SBlock> + 'static,
     SClient::Api: SystemDomainApi<SBlock, NumberFor<PBlock>, PBlock::Hash>,
+    PClient: HeaderBackend<PBlock> + 'static,
     Backend: sc_client_api::Backend<Block> + 'static,
     TransactionFor<Backend, Block>: sp_trie::HashDBT<HashFor<Block>, sp_trie::DBValue>,
     TransactionPool: sc_transaction_pool_api::TransactionPool<Block = Block> + 'static,
diff --git a/domains/client/domain-executor/src/domain_block_processor.rs b/domains/client/domain-executor/src/domain_block_processor.rs
index 092b93102bd..e7f5ef6c66f 100644
--- a/domains/client/domain-executor/src/domain_block_processor.rs
+++ b/domains/client/domain-executor/src/domain_block_processor.rs
@@ -40,7 +40,7 @@ where
     primary_chain_client: Arc<PClient>,
     primary_network_sync_oracle: Arc<dyn SyncOracle + Send + Sync>,
     backend: Arc<Backend>,
-    fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, Backend, E>,
+    fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, PClient, Backend, E>,
 }
 
 impl<Block, PBlock, Client, PClient, Backend, E> Clone
@@ -105,7 +105,7 @@ where
         primary_chain_client: Arc<PClient>,
         primary_network_sync_oracle: Arc<dyn SyncOracle + Send + Sync>,
         backend: Arc<Backend>,
-        fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, Backend, E>,
+        fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, PClient, Backend, E>,
     ) -> Self {
         Self {
             domain_id,
diff --git a/domains/client/domain-executor/src/fraud_proof.rs b/domains/client/domain-executor/src/fraud_proof.rs
index b7437ad89e1..f562bdd9b4d 100644
--- a/domains/client/domain-executor/src/fraud_proof.rs
+++ b/domains/client/domain-executor/src/fraud_proof.rs
@@ -29,20 +29,22 @@ pub enum FraudProofError {
     RuntimeApi(#[from] sp_api::ApiError),
 }
 
-pub struct FraudProofGenerator<Block, PBlock, Client, Backend, E> {
+pub struct FraudProofGenerator<Block, PBlock, Client, PClient, Backend, E> {
     client: Arc<Client>,
+    primary_chain_client: Arc<PClient>,
     spawner: Box<dyn SpawnNamed + Send + Sync>,
     backend: Arc<Backend>,
     code_executor: Arc<E>,
     _phantom: PhantomData<(Block, PBlock)>,
 }
 
-impl<Block, PBlock, Client, Backend, E> Clone
-    for FraudProofGenerator<Block, PBlock, Client, Backend, E>
+impl<Block, PBlock, Client, PClient, Backend, E> Clone
+    for FraudProofGenerator<Block, PBlock, Client, PClient, Backend, E>
 {
     fn clone(&self) -> Self {
         Self {
             client: self.client.clone(),
+            primary_chain_client: self.primary_chain_client.clone(),
             spawner: self.spawner.clone(),
             backend: self.backend.clone(),
             code_executor: self.code_executor.clone(),
@@ -51,7 +53,8 @@ impl<Block, PBlock, Client, Backend, E> Clone
     }
 }
 
-impl<Block, PBlock, Client, Backend, E> FraudProofGenerator<Block, PBlock, Client, Backend, E>
+impl<Block, PBlock, Client, PClient, Backend, E>
+    FraudProofGenerator<Block, PBlock, Client, PClient, Backend, E>
 where
     Block: BlockT,
     PBlock: BlockT,
@@ -59,18 +62,21 @@ where
         HeaderBackend<Block> + BlockBackend<Block> + AuxStore + ProvideRuntimeApi<Block> + 'static,
     Client::Api: sp_block_builder::BlockBuilder<Block>
         + sp_api::ApiExt<Block, StateBackend = StateBackendFor<Backend, Block>>,
+    PClient: HeaderBackend<PBlock> + 'static,
     Backend: sc_client_api::Backend<Block> + Send + Sync + 'static,
     TransactionFor<Backend, Block>: sp_trie::HashDBT<HashFor<Block>, sp_trie::DBValue>,
     E: CodeExecutor,
 {
     pub fn new(
         client: Arc<Client>,
+        primary_chain_client: Arc<PClient>,
         spawner: Box<dyn SpawnNamed + Send + Sync>,
         backend: Arc<Backend>,
         code_executor: Arc<E>,
     ) -> Self {
         Self {
             client,
+            primary_chain_client,
             spawner,
             backend,
             code_executor,
@@ -115,6 +121,22 @@ where
             },
         )?;
 
+        let primary_parent_hash = H256::decode(
+            &mut self
+                .primary_chain_client
+                .header(local_receipt.primary_hash)?
+                .ok_or_else(|| {
+                    sp_blockchain::Error::Backend(format!(
+                        "Header not found for primary {:?}",
+                        local_receipt.primary_hash
+                    ))
+                })?
+                .parent_hash()
+                .encode()
+                .as_slice(),
+        )
+        .map_err(|_| FraudProofError::InvalidStateRootType)?;
+
         // TODO: abstract the execution proof impl to be reusable in the test.
         let invalid_state_transition_proof = if local_trace_index == 0 {
             // `initialize_block` execution proof.
@@ -128,7 +150,9 @@ where
                 parent_header.hash(),
                 Default::default(),
             );
-            let execution_phase = ExecutionPhase::InitializeBlock;
+            let execution_phase = ExecutionPhase::InitializeBlock {
+                domain_parent_hash: as_h256(&parent_header.hash())?,
+            };
             let initialize_block_call_data = new_header.encode();
 
             let proof = prover.prove_execution::<TransactionFor<Backend, Block>>(
@@ -142,7 +166,7 @@ where
                 domain_id,
                 bad_receipt_hash,
                 parent_number,
-                parent_hash: as_h256(&parent_header.hash())?,
+                primary_parent_hash,
                 pre_state_root,
                 post_state_root,
                 proof,
@@ -183,7 +207,7 @@ where
                 domain_id,
                 bad_receipt_hash,
                 parent_number,
-                parent_hash: as_h256(&parent_header.hash())?,
+                primary_parent_hash,
                 pre_state_root,
                 post_state_root,
                 proof,
@@ -206,7 +230,7 @@ where
                 domain_id,
                 bad_receipt_hash,
                 parent_number,
-                parent_hash: as_h256(&parent_header.hash())?,
+                primary_parent_hash,
                 pre_state_root,
                 post_state_root,
                 proof,
diff --git a/domains/client/domain-executor/src/gossip_message_validator.rs b/domains/client/domain-executor/src/gossip_message_validator.rs
index 8414847ffed..46c25f7086f 100644
--- a/domains/client/domain-executor/src/gossip_message_validator.rs
+++ b/domains/client/domain-executor/src/gossip_message_validator.rs
@@ -45,14 +45,14 @@ impl From<sp_blockchain::Error> for GossipMessageError {
 }
 
 /// Base domain gossip message validator.
-pub struct GossipMessageValidator<Block, PBlock, Client, Backend, E> {
+pub struct GossipMessageValidator<Block, PBlock, Client, PClient, Backend, E> {
     client: Arc<Client>,
     spawner: Box<dyn SpawnNamed + Send + Sync>,
-    fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, Backend, E>,
+    fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, PClient, Backend, E>,
 }
 
-impl<Block, PBlock, Client, Backend, E> Clone
-    for GossipMessageValidator<Block, PBlock, Client, Backend, E>
+impl<Block, PBlock, Client, PClient, Backend, E> Clone
+    for GossipMessageValidator<Block, PBlock, Client, PClient, Backend, E>
 {
     fn clone(&self) -> Self {
         Self {
@@ -63,7 +63,8 @@ impl<Block, PBlock, Client, Backend, E> Clone
     }
 }
 
-impl<Block, PBlock, Client, Backend, E> GossipMessageValidator<Block, PBlock, Client, Backend, E>
+impl<Block, PBlock, Client, PClient, Backend, E>
+    GossipMessageValidator<Block, PBlock, Client, PClient, Backend, E>
 where
     Block: BlockT,
     PBlock: BlockT,
@@ -75,6 +76,7 @@ where
         + 'static,
     Client::Api: sp_block_builder::BlockBuilder<Block>
         + sp_api::ApiExt<Block, StateBackend = StateBackendFor<Backend, Block>>,
+    PClient: HeaderBackend<PBlock> + 'static,
     Backend: sc_client_api::Backend<Block> + 'static,
     TransactionFor<Backend, Block>: sp_trie::HashDBT<HashFor<Block>, sp_trie::DBValue>,
     E: CodeExecutor,
@@ -82,7 +84,7 @@ where
     pub(crate) fn new(
         client: Arc<Client>,
         spawner: Box<dyn SpawnNamed + Send + Sync>,
-        fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, Backend, E>,
+        fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, PClient, Backend, E>,
     ) -> Self {
         Self {
             client,
diff --git a/domains/client/domain-executor/src/system_executor.rs b/domains/client/domain-executor/src/system_executor.rs
index a079c568cf0..8c270a8bc96 100644
--- a/domains/client/domain-executor/src/system_executor.rs
+++ b/domains/client/domain-executor/src/system_executor.rs
@@ -33,7 +33,7 @@ where
     spawner: Box<dyn SpawnNamed + Send + Sync>,
     transaction_pool: Arc<TransactionPool>,
     backend: Arc<Backend>,
-    fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, Backend, E>,
+    fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, PClient, Backend, E>,
     bundle_processor: SystemBundleProcessor<Block, PBlock, Client, PClient, Backend, E>,
 }
 
@@ -133,6 +133,7 @@ where
 
         let fraud_proof_generator = FraudProofGenerator::new(
             params.client.clone(),
+            params.primary_chain_client.clone(),
             params.spawner.clone(),
             params.backend.clone(),
             params.code_executor,
@@ -181,7 +182,9 @@ where
         })
     }
 
-    pub fn fraud_proof_generator(&self) -> FraudProofGenerator<Block, PBlock, Client, Backend, E> {
+    pub fn fraud_proof_generator(
+        &self,
+    ) -> FraudProofGenerator<Block, PBlock, Client, PClient, Backend, E> {
         self.fraud_proof_generator.clone()
     }
 
diff --git a/domains/client/domain-executor/src/system_gossip_message_validator.rs b/domains/client/domain-executor/src/system_gossip_message_validator.rs
index fa5def9c861..6d33abbc3b4 100644
--- a/domains/client/domain-executor/src/system_gossip_message_validator.rs
+++ b/domains/client/domain-executor/src/system_gossip_message_validator.rs
@@ -19,6 +19,7 @@ pub struct SystemGossipMessageValidator<
     Block,
     PBlock,
     Client,
+    PClient,
     TransactionPool,
     Backend,
     E,
@@ -27,14 +28,15 @@ pub struct SystemGossipMessageValidator<
     parent_chain: ParentChain,
     client: Arc<Client>,
     transaction_pool: Arc<TransactionPool>,
-    gossip_message_validator: GossipMessageValidator<Block, PBlock, Client, Backend, E>,
+    gossip_message_validator: GossipMessageValidator<Block, PBlock, Client, PClient, Backend, E>,
 }
 
-impl<Block, PBlock, Client, TransactionPool, Backend, E, ParentChain> Clone
+impl<Block, PBlock, Client, PClient, TransactionPool, Backend, E, ParentChain> Clone
     for SystemGossipMessageValidator<
         Block,
         PBlock,
         Client,
+        PClient,
         TransactionPool,
         Backend,
         E,
@@ -53,8 +55,17 @@ where
     }
 }
 
-impl<Block, PBlock, Client, TransactionPool, Backend, E, ParentChain>
-    SystemGossipMessageValidator<Block, PBlock, Client, TransactionPool, Backend, E, ParentChain>
+impl<Block, PBlock, Client, PClient, TransactionPool, Backend, E, ParentChain>
+    SystemGossipMessageValidator<
+        Block,
+        PBlock,
+        Client,
+        PClient,
+        TransactionPool,
+        Backend,
+        E,
+        ParentChain,
+    >
 where
     Block: BlockT,
     PBlock: BlockT,
@@ -67,6 +78,7 @@ where
     Client::Api: SystemDomainApi<Block, NumberFor<PBlock>, PBlock::Hash>
         + sp_block_builder::BlockBuilder<Block>
         + sp_api::ApiExt<Block, StateBackend = StateBackendFor<Backend, Block>>,
+    PClient: HeaderBackend<PBlock> + 'static,
     Backend: sc_client_api::Backend<Block> + 'static,
     TransactionFor<Backend, Block>: sp_trie::HashDBT<HashFor<Block>, sp_trie::DBValue>,
     TransactionPool: sc_transaction_pool_api::TransactionPool<Block = Block> + 'static,
@@ -78,7 +90,7 @@ where
         client: Arc<Client>,
         spawner: Box<dyn SpawnNamed + Send + Sync>,
         transaction_pool: Arc<TransactionPool>,
-        fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, Backend, E>,
+        fraud_proof_generator: FraudProofGenerator<Block, PBlock, Client, PClient, Backend, E>,
     ) -> Self {
         let gossip_message_validator =
             GossipMessageValidator::new(client.clone(), spawner, fraud_proof_generator);
@@ -91,12 +103,13 @@ where
     }
 }
 
-impl<Block, PBlock, Client, TransactionPool, Backend, E, ParentChain>
+impl<Block, PBlock, Client, PClient, TransactionPool, Backend, E, ParentChain>
     GossipMessageHandler<PBlock, Block>
     for SystemGossipMessageValidator<
         Block,
         PBlock,
         Client,
+        PClient,
         TransactionPool,
         Backend,
         E,
@@ -115,6 +128,7 @@ where
         + sp_block_builder::BlockBuilder<Block>
         + sp_api::ApiExt<Block, StateBackend = StateBackendFor<Backend, Block>>,
     Backend: sc_client_api::Backend<Block> + 'static,
+    PClient: HeaderBackend<PBlock> + 'static,
     TransactionFor<Backend, Block>: sp_trie::HashDBT<HashFor<Block>, sp_trie::DBValue>,
     TransactionPool: sc_transaction_pool_api::TransactionPool<Block = Block> + 'static,
     E: CodeExecutor,
diff --git a/domains/client/domain-executor/src/tests.rs b/domains/client/domain-executor/src/tests.rs
index e3422a74e41..06168a80a39 100644
--- a/domains/client/domain-executor/src/tests.rs
+++ b/domains/client/domain-executor/src/tests.rs
@@ -154,7 +154,9 @@ async fn fraud_proof_verification_in_tx_pool_should_work() {
         parent_header.hash(),
         digest,
     );
-    let execution_phase = ExecutionPhase::InitializeBlock;
+    let execution_phase = ExecutionPhase::InitializeBlock {
+        domain_parent_hash: parent_header.hash(),
+    };
     let initialize_block_call_data = new_header.encode();
 
     let storage_proof = prover
@@ -178,7 +180,7 @@ async fn fraud_proof_verification_in_tx_pool_should_work() {
         domain_id: DomainId::SYSTEM,
         bad_receipt_hash: Hash::random(),
         parent_number: parent_number_ferdie,
-        parent_hash: parent_hash_ferdie,
+        primary_parent_hash: parent_hash_ferdie,
         pre_state_root: *parent_header.state_root(),
         post_state_root: intermediate_roots[0].into(),
         proof: storage_proof,
diff --git a/domains/service/src/core_domain.rs b/domains/service/src/core_domain.rs
index 5b52c3fd4e4..67ad4c486d3 100644
--- a/domains/service/src/core_domain.rs
+++ b/domains/service/src/core_domain.rs
@@ -407,7 +407,7 @@ where
     .await?;
 
     let gossip_message_validator =
-        CoreGossipMessageValidator::<_, SBlock, PBlock, _, SClient, _, _, _, _>::new(
+        CoreGossipMessageValidator::<_, SBlock, PBlock, _, SClient, _, _, _, _, _>::new(
             CoreDomainParentChain::<_, SBlock, PBlock>::new(
                 system_domain_client.clone(),
                 domain_id,