diff --git a/accounts/src/key_management/mod.rs b/accounts/src/key_management/mod.rs
index 9b63a36..6fa1462 100644
--- a/accounts/src/key_management/mod.rs
+++ b/accounts/src/key_management/mod.rs
@@ -61,7 +61,7 @@ impl AddressKeyHolder {
     pub fn get_pub_account_signing_key(&self) -> SigningKey {
         let field_bytes = FieldBytes::from_slice(&self.pub_account_signing_key);
         // TODO: remove unwrap
-        SigningKey::from_bytes(&field_bytes).unwrap()
+        SigningKey::from_bytes(field_bytes).unwrap()
     }
 
     pub fn calculate_shared_secret_receiver(
diff --git a/sequencer_core/src/lib.rs b/sequencer_core/src/lib.rs
index 5ac482e..bfde1f6 100644
--- a/sequencer_core/src/lib.rs
+++ b/sequencer_core/src/lib.rs
@@ -92,12 +92,18 @@ impl SequencerCore {
 
         let tx_hash = *tx.hash();
 
+        let mempool_size = self.mempool.len();
+
+        if mempool_size >= self.sequencer_config.max_num_tx_in_block {
+            return Err(TransactionMalformationErrorKind::MempoolFullForRound { tx: tx_hash });
+        }
+
         let curr_sequencer_roots = self.get_tree_roots();
 
         if tx_roots != curr_sequencer_roots {
             return Err(
                 TransactionMalformationErrorKind::ChainStateFurtherThanTransactionState {
-                    tx: hash,
+                    tx: tx_hash,
                 },
             );
         }
@@ -111,7 +117,7 @@ impl SequencerCore {
                     //Public transactions can not make private operations.
                     return Err(
                         TransactionMalformationErrorKind::PublicTransactionChangedPrivateData {
-                            tx: hash,
+                            tx: tx_hash,
                         },
                     );
                 }
@@ -123,7 +129,7 @@ impl SequencerCore {
                     //between public and private state.
                     return Err(
                         TransactionMalformationErrorKind::PrivateTransactionChangedPublicData {
-                            tx: hash,
+                            tx: tx_hash,
                         },
                     );
                 }
@@ -132,7 +138,7 @@ impl SequencerCore {
         };
 
         //Tree checks
-        let tx_tree_check = self.store.pub_tx_store.get_tx(hash).is_some();
+        let tx_tree_check = self.store.pub_tx_store.get_tx(tx_hash).is_some();
         let nullifier_tree_check = nullifier_created_hashes.iter().any(|nullifier_hash| {
             self.store.nullifier_store.contains(&UTXONullifier {
                 utxo_hash: *nullifier_hash,
@@ -232,7 +238,7 @@ impl SequencerCore {
             .pop_size(self.sequencer_config.max_num_tx_in_block);
 
         for tx in &transactions {
-            self.execute_check_transaction_on_state(&tx)?;
+            self.execute_check_transaction_on_state(tx)?;
         }
 
         let prev_block_hash = self