diff --git a/rust/sealevel/libraries/multisig-ism/src/test_data.rs b/rust/sealevel/libraries/multisig-ism/src/test_data.rs
index 78ca51b35e..ed3c86fb24 100644
--- a/rust/sealevel/libraries/multisig-ism/src/test_data.rs
+++ b/rust/sealevel/libraries/multisig-ism/src/test_data.rs
@@ -17,7 +17,7 @@ const DESTINATION_DOMAIN: u32 = 4321u32;
 
 pub fn get_multisig_ism_test_data() -> MultisigIsmTestData {
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 69,
         origin: ORIGIN_DOMAIN,
         sender: H256::from_str(
diff --git a/rust/sealevel/programs/hyperlane-sealevel-token-collateral/tests/functional.rs b/rust/sealevel/programs/hyperlane-sealevel-token-collateral/tests/functional.rs
index 7ac4bd8e20..4a1b2b57f2 100644
--- a/rust/sealevel/programs/hyperlane-sealevel-token-collateral/tests/functional.rs
+++ b/rust/sealevel/programs/hyperlane-sealevel-token-collateral/tests/functional.rs
@@ -725,7 +725,7 @@ async fn test_transfer_remote(spl_token_program_id: Pubkey) {
         .unwrap();
 
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: LOCAL_DOMAIN,
         sender: program_id.to_bytes().into(),
@@ -869,7 +869,7 @@ async fn transfer_from_remote(
         );
 
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: origin_override.unwrap_or(REMOTE_DOMAIN),
         // Default to the remote router as the sender
diff --git a/rust/sealevel/programs/hyperlane-sealevel-token-native/tests/functional.rs b/rust/sealevel/programs/hyperlane-sealevel-token-native/tests/functional.rs
index ec5f6e438d..5014dcae5b 100644
--- a/rust/sealevel/programs/hyperlane-sealevel-token-native/tests/functional.rs
+++ b/rust/sealevel/programs/hyperlane-sealevel-token-native/tests/functional.rs
@@ -510,7 +510,7 @@ async fn test_transfer_remote() {
         .unwrap();
 
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: LOCAL_DOMAIN,
         sender: program_id.to_bytes().into(),
@@ -616,7 +616,7 @@ async fn transfer_from_remote(
     let recipient: H256 = recipient_pubkey.to_bytes().into();
 
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: origin_override.unwrap_or(REMOTE_DOMAIN),
         // Default to the remote router as the sender
diff --git a/rust/sealevel/programs/hyperlane-sealevel-token/tests/functional.rs b/rust/sealevel/programs/hyperlane-sealevel-token/tests/functional.rs
index 7cac39aee5..adac2a05fd 100644
--- a/rust/sealevel/programs/hyperlane-sealevel-token/tests/functional.rs
+++ b/rust/sealevel/programs/hyperlane-sealevel-token/tests/functional.rs
@@ -451,7 +451,7 @@ async fn transfer_from_remote(
         );
 
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: origin_override.unwrap_or(REMOTE_DOMAIN),
         // Default to the remote router as the sender
@@ -783,7 +783,7 @@ async fn test_transfer_remote() {
         .unwrap();
 
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: LOCAL_DOMAIN,
         sender: program_id.to_bytes().into(),
diff --git a/rust/sealevel/programs/ism/multisig-ism-message-id/tests/functional.rs b/rust/sealevel/programs/ism/multisig-ism-message-id/tests/functional.rs
index b7820649fc..efaa97928f 100644
--- a/rust/sealevel/programs/ism/multisig-ism-message-id/tests/functional.rs
+++ b/rust/sealevel/programs/ism/multisig-ism-message-id/tests/functional.rs
@@ -299,7 +299,7 @@ async fn test_set_validators_and_threshold_creates_pda_account() {
     // to fetch the account metas required for the instruction.
 
     let test_message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: domain,
         sender: H256::random(),
diff --git a/rust/sealevel/programs/mailbox-test/src/functional.rs b/rust/sealevel/programs/mailbox-test/src/functional.rs
index c826b6ed0c..c551eda3c6 100644
--- a/rust/sealevel/programs/mailbox-test/src/functional.rs
+++ b/rust/sealevel/programs/mailbox-test/src/functional.rs
@@ -183,7 +183,7 @@ async fn test_dispatch_from_eoa() {
         .unwrap();
 
     let expected_message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: LOCAL_DOMAIN,
         sender: payer.pubkey().to_bytes().into(),
@@ -238,7 +238,7 @@ async fn test_dispatch_from_eoa() {
         .unwrap();
 
     let expected_message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 1,
         origin: LOCAL_DOMAIN,
         sender: payer.pubkey().to_bytes().into(),
@@ -300,7 +300,7 @@ async fn test_dispatch_from_program() {
             .unwrap();
 
     let expected_message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: LOCAL_DOMAIN,
         // The sender should be the program ID because its dispatch authority signed
@@ -389,7 +389,7 @@ async fn test_dispatch_returns_message_id() {
         message_body: message_body.clone(),
     };
     let expected_message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: LOCAL_DOMAIN,
         sender: payer.pubkey().to_bytes().into(),
@@ -574,7 +574,7 @@ async fn test_process_successful_verify_and_handle() {
     let recipient_id = hyperlane_sealevel_test_send_receiver::id();
 
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: REMOTE_DOMAIN,
         sender: payer.pubkey().to_bytes().into(),
@@ -605,7 +605,7 @@ async fn test_process_successful_verify_and_handle() {
 
     // Send another to illustrate that the sequence is incremented
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: REMOTE_DOMAIN,
         sender: payer.pubkey().to_bytes().into(),
@@ -647,7 +647,7 @@ async fn test_process_errors_if_message_already_processed() {
     let recipient_id = hyperlane_sealevel_test_send_receiver::id();
 
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: REMOTE_DOMAIN,
         sender: payer.pubkey().to_bytes().into(),
@@ -697,7 +697,7 @@ async fn test_process_errors_if_ism_verify_fails() {
     test_ism.set_accept(false).await.unwrap();
 
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: REMOTE_DOMAIN,
         sender: payer.pubkey().to_bytes().into(),
@@ -743,7 +743,7 @@ async fn test_process_errors_if_recipient_handle_fails() {
         .unwrap();
 
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: REMOTE_DOMAIN,
         sender: payer.pubkey().to_bytes().into(),
@@ -784,7 +784,7 @@ async fn test_process_errors_if_incorrect_destination_domain() {
     let recipient_id = hyperlane_sealevel_test_send_receiver::id();
 
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: REMOTE_DOMAIN,
         sender: payer.pubkey().to_bytes().into(),
@@ -905,7 +905,7 @@ async fn test_process_errors_if_reentrant() {
     let recipient_id = hyperlane_sealevel_test_send_receiver::id();
 
     let message = HyperlaneMessage {
-        version: 0,
+        version: 3,
         nonce: 0,
         origin: REMOTE_DOMAIN,
         sender: payer.pubkey().to_bytes().into(),
diff --git a/rust/sealevel/programs/mailbox/src/instruction.rs b/rust/sealevel/programs/mailbox/src/instruction.rs
index 78a553f92d..89d4335984 100644
--- a/rust/sealevel/programs/mailbox/src/instruction.rs
+++ b/rust/sealevel/programs/mailbox/src/instruction.rs
@@ -11,7 +11,7 @@ use solana_program::{
 use crate::{mailbox_inbox_pda_seeds, mailbox_outbox_pda_seeds};
 
 /// The current message version.
-pub const VERSION: u8 = 0;
+pub const VERSION: u8 = 3;
 
 /// Maximum bytes per message = 2 KiB (somewhat arbitrarily set to begin).
 pub const MAX_MESSAGE_BODY_BYTES: usize = 2 * 2_usize.pow(10);