diff --git a/noir-projects/aztec-nr/aztec/src/hash.nr b/noir-projects/aztec-nr/aztec/src/hash.nr
index 7c5623cfd327..8beff1afb1d1 100644
--- a/noir-projects/aztec-nr/aztec/src/hash.nr
+++ b/noir-projects/aztec-nr/aztec/src/hash.nr
@@ -1,15 +1,53 @@
 use dep::protocol_types::{
-    address::AztecAddress, 
-    constants::GENERATOR_INDEX__L1_TO_L2_MESSAGE_SECRET, 
-    hash::{pedersen_hash, silo_nullifier}};
+    address::{AztecAddress, EthAddress},
+    constants::{GENERATOR_INDEX__L1_TO_L2_MESSAGE_SECRET, GENERATOR_INDEX__NULLIFIER},
+    hash::{pedersen_hash, silo_nullifier}
+};
 
-use dep::protocol_types::hash::{hash_args, hash_args_array};
+use dep::protocol_types::hash::{hash_args, hash_args_array, sha256_to_field};
 
 pub fn compute_secret_hash(secret: Field) -> Field {
     // TODO(#1205) This is probably not the right index to use
     pedersen_hash([secret], GENERATOR_INDEX__L1_TO_L2_MESSAGE_SECRET)
 }
 
+pub fn compute_message_hash(
+    sender: EthAddress,
+    chain_id: Field,
+    recipient: AztecAddress,
+    version: Field,
+    content: Field,
+    secret_hash: Field
+) -> Field {
+    let mut hash_bytes = [0 as u8; 192];
+    let sender_bytes = sender.to_field().to_be_bytes(32);
+    let chain_id_bytes = chain_id.to_be_bytes(32);
+    let recipient_bytes = recipient.to_field().to_be_bytes(32);
+    let version_bytes = version.to_be_bytes(32);
+    let content_bytes = content.to_be_bytes(32);
+    let secret_hash_bytes = secret_hash.to_be_bytes(32);
+
+    for i in 0..32 {
+        hash_bytes[i] = sender_bytes[i];
+        hash_bytes[i + 32] = chain_id_bytes[i];
+        hash_bytes[i + 64] = recipient_bytes[i];
+        hash_bytes[i + 96] = version_bytes[i];
+        hash_bytes[i + 128] = content_bytes[i];
+        hash_bytes[i + 160] = secret_hash_bytes[i];
+    }
+
+    sha256_to_field(hash_bytes)
+}
+
+// The nullifier of a l1 to l2 message is the hash of the message salted with the secret and index of the message hash
+// in the L1 to L2 message tree
+pub fn compute_message_nullifier(message_hash: Field, secret: Field, leaf_index: Field) -> Field {
+    pedersen_hash(
+        [message_hash, secret, leaf_index],
+        GENERATOR_INDEX__NULLIFIER
+    )
+}
+
 pub fn compute_siloed_nullifier(address: AztecAddress, nullifier: Field) -> Field {
     silo_nullifier(address, nullifier)
-}
\ No newline at end of file
+}
diff --git a/noir-projects/aztec-nr/aztec/src/messaging.nr b/noir-projects/aztec-nr/aztec/src/messaging.nr
index 6e3943677096..3f649e9e4bf7 100644
--- a/noir-projects/aztec-nr/aztec/src/messaging.nr
+++ b/noir-projects/aztec-nr/aztec/src/messaging.nr
@@ -1,9 +1,9 @@
-mod l1_to_l2_message;
-
-use crate::oracle::get_l1_to_l2_membership_witness::get_l1_to_l2_membership_witness;
+use crate::{
+    hash::{compute_secret_hash, compute_message_hash, compute_message_nullifier},
+    oracle::get_l1_to_l2_membership_witness::get_l1_to_l2_membership_witness
+};
 
 use dep::std::merkle::compute_merkle_root;
-use crate::messaging::l1_to_l2_message::L1ToL2Message;
 use dep::protocol_types::{constants::L1_TO_L2_MSG_TREE_HEIGHT, address::{AztecAddress, EthAddress}, utils::arr_copy_slice};
 
 pub fn process_l1_to_l2_message(
@@ -15,15 +15,8 @@ pub fn process_l1_to_l2_message(
     content: Field,
     secret: Field
 ) -> Field {
-    let mut msg = L1ToL2Message::new(
-        portal_contract_address,
-        chain_id,
-        storage_contract_address,
-        version,
-        content,
-        secret
-    );
-    let message_hash = msg.hash();
+    let secret_hash = compute_secret_hash(secret);
+    let message_hash = compute_message_hash(portal_contract_address, chain_id, storage_contract_address, version, content, secret_hash);
 
     let returned_message = get_l1_to_l2_membership_witness(storage_contract_address, message_hash, secret);
     let leaf_index = returned_message[0];
@@ -34,12 +27,5 @@ pub fn process_l1_to_l2_message(
     let root = compute_merkle_root(message_hash, leaf_index, sibling_path);
     assert(root == l1_to_l2_root, "Message not in state");
 
-    // Note: Had to add this line to make it work (wasted an hour debugging this). L1ToL2Message noir struct is
-    // an abomination and it would not have ever got to that state if people followed the logical rule of 
-    // "deserialize(serialize(object)) == object" always being true (there are a few params which are not
-    // serialzied). Will refactor that in a separate PR.
-    // TODO(#5420)
-    msg.tree_index = leaf_index;
-
-    msg.compute_nullifier()
+    compute_message_nullifier(message_hash, secret, leaf_index)
 }
diff --git a/noir-projects/aztec-nr/aztec/src/messaging/l1_to_l2_message.nr b/noir-projects/aztec-nr/aztec/src/messaging/l1_to_l2_message.nr
deleted file mode 100644
index 6fd9a65e60c5..000000000000
--- a/noir-projects/aztec-nr/aztec/src/messaging/l1_to_l2_message.nr
+++ /dev/null
@@ -1,89 +0,0 @@
-use dep::protocol_types::{
-    address::{AztecAddress, EthAddress},
-    constants::{L1_TO_L2_MESSAGE_LENGTH, GENERATOR_INDEX__NULLIFIER, GENERATOR_INDEX__L1_TO_L2_MESSAGE_SECRET},
-    hash::{pedersen_hash, sha256_to_field}
-};
-
-struct L1ToL2Message {
-    sender: EthAddress,
-    chain_id: Field,
-    recipient: AztecAddress,
-    version: Field,
-    content: Field,
-    secret: Field,
-    secret_hash: Field,
-    tree_index: Field
-}
-
-impl L1ToL2Message {
-    pub fn new(
-        sender: EthAddress,
-        chain_id: Field,
-        recipient: AztecAddress,
-        version: Field,
-        content: Field,
-        secret: Field
-    ) -> L1ToL2Message {
-        let secret_hash = pedersen_hash([secret], GENERATOR_INDEX__L1_TO_L2_MESSAGE_SECRET);
-        Self {
-            sender,
-            chain_id,
-            recipient,
-            version,
-            content,
-            secret,
-            secret_hash,
-            tree_index: 0
-        }
-    }
-
-    pub fn deserialize(
-        fields: [Field; L1_TO_L2_MESSAGE_LENGTH],
-        secret: Field, // TODO(#5420): refactor this so that this param does not have to be passed separately
-        tree_index: Field // TODO(#5420): refactor this so that this param does not have to be passed separately
-    ) -> L1ToL2Message {
-        L1ToL2Message {
-            sender: EthAddress::from_field(fields[0]),
-            chain_id: fields[1],
-            recipient: AztecAddress::from_field(fields[2]),
-            version: fields[3],
-            content: fields[4],
-            secret,
-            secret_hash: fields[5],
-            tree_index
-        }
-    }
-
-    fn hash(self: Self) -> Field {
-        let mut hash_bytes = [0 as u8; 192];
-        let sender_bytes = self.sender.to_field().to_be_bytes(32);
-        let chain_id_bytes = self.chain_id.to_be_bytes(32);
-        let recipient_bytes = self.recipient.to_field().to_be_bytes(32);
-        let version_bytes = self.version.to_be_bytes(32);
-        let content_bytes = self.content.to_be_bytes(32);
-        let secret_hash_bytes = self.secret_hash.to_be_bytes(32);
-
-        for i in 0..32 {
-            hash_bytes[i] = sender_bytes[i];
-            hash_bytes[i + 32] = chain_id_bytes[i];
-            hash_bytes[i + 64] = recipient_bytes[i];
-            hash_bytes[i + 96] = version_bytes[i];
-            hash_bytes[i + 128] = content_bytes[i];
-            hash_bytes[i + 160] = secret_hash_bytes[i];
-        }
-
-        let message_hash = sha256_to_field(hash_bytes);
-        message_hash
-    }
-
-    // The nullifier of a l1 to l2 message is the hash of the message salted with the secret and tree index
-    // docs:start:l1_to_l2_message_compute_nullifier
-    pub fn compute_nullifier(self: Self) -> Field {
-        let message_hash = self.hash();
-        pedersen_hash(
-            [message_hash, self.secret, self.tree_index],
-            GENERATOR_INDEX__NULLIFIER
-        )
-    }
-    // docs:end:l1_to_l2_message_compute_nullifier
-}