diff --git a/contracts/axelar-gateway/src/contract.rs b/contracts/axelar-gateway/src/contract.rs
index eda4bdf0..795b467d 100644
--- a/contracts/axelar-gateway/src/contract.rs
+++ b/contracts/axelar-gateway/src/contract.rs
@@ -25,15 +25,15 @@ pub struct AxelarGateway;
 
 #[contractimpl]
 impl UpgradeableInterface for AxelarGateway {
-    fn version(env: Env) -> String {
-        String::from_str(&env, CONTRACT_VERSION)
+    fn version(env: &Env) -> String {
+        String::from_str(env, CONTRACT_VERSION)
     }
 
-    fn upgrade(env: Env, new_wasm_hash: BytesN<32>) {
-        Self::owner(&env).require_auth();
+    fn upgrade(env: &Env, new_wasm_hash: BytesN<32>) {
+        Self::owner(env).require_auth();
 
         env.deployer().update_current_contract_wasm(new_wasm_hash);
-        Self::start_migration(&env);
+        Self::start_migration(env);
     }
 }
 
@@ -64,13 +64,15 @@ impl AxelarGateway {
     }
 
     /// Migrate the contract state after upgrading the contract code. the migration_data type can be adjusted as needed.
-    pub fn migrate(env: Env, migration_data: ()) -> Result<(), ContractError> {
+    pub fn migrate(env: &Env, migration_data: ()) -> Result<(), ContractError> {
         // This function should not get modified.
         // Custom migration logic that changes from version to version should be added in the run_migration function
-        Self::ensure_is_migrating(&env)?;
+        Self::ensure_is_migrating(env)?;
 
-        Self::run_migration(&env, migration_data);
-        Self::complete_migration(&env);
+        Self::run_migration(env, migration_data);
+        Self::complete_migration(env);
+
+        event::upgraded(env, &Self::version(env));
 
         Ok(())
     }
diff --git a/contracts/axelar-gateway/src/error.rs b/contracts/axelar-gateway/src/error.rs
index 0f91c372..ff2d76eb 100644
--- a/contracts/axelar-gateway/src/error.rs
+++ b/contracts/axelar-gateway/src/error.rs
@@ -4,7 +4,7 @@ use soroban_sdk::contracterror;
 #[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
 #[repr(u32)]
 pub enum ContractError {
-    // Auth
+    /// Auth
     InvalidThreshold = 1,
     InvalidProof = 2,
     InvalidSigners = 3,
@@ -16,7 +16,8 @@ pub enum ContractError {
     DuplicateSigners = 9,
     InvalidSignersHash = 10,
     InvalidEpoch = 11,
-    // Messages
+    /// Messages
     EmptyMessages = 12,
+    /// Upgradeable
     MigrationNotAllowed = 13,
 }
diff --git a/contracts/axelar-gateway/src/event.rs b/contracts/axelar-gateway/src/event.rs
index 3173f818..d22e7695 100644
--- a/contracts/axelar-gateway/src/event.rs
+++ b/contracts/axelar-gateway/src/event.rs
@@ -51,3 +51,8 @@ pub fn transfer_ownership(env: &Env, previous_owner: Address, new_owner: Address
     );
     env.events().publish(topics, ());
 }
+
+pub fn upgraded(env: &Env, version: &String) {
+    env.events()
+        .publish((Symbol::new(env, "upgraded"),), (version.to_val(),));
+}
diff --git a/contracts/axelar-gateway/src/storage_types.rs b/contracts/axelar-gateway/src/storage_types.rs
index bca6d200..40265b76 100644
--- a/contracts/axelar-gateway/src/storage_types.rs
+++ b/contracts/axelar-gateway/src/storage_types.rs
@@ -22,6 +22,7 @@ pub enum DataKey {
     Owner,
     Operator,
     MessageApproval(MessageApprovalKey),
+    /// Upgradeable
     Migrating,
     /// Auth Module
     PreviousSignerRetention,
diff --git a/contracts/upgrader/tests/utils/dummy_contract.rs b/contracts/upgrader/tests/utils/dummy_contract.rs
index a0314380..d0e6395a 100644
--- a/contracts/upgrader/tests/utils/dummy_contract.rs
+++ b/contracts/upgrader/tests/utils/dummy_contract.rs
@@ -8,12 +8,12 @@ pub struct DummyContract;
 /// Dummy contract logic before upgrade
 #[contractimpl]
 impl UpgradeableInterface for DummyContract {
-    fn version(env: Env) -> soroban_sdk::String {
-        soroban_sdk::String::from_str(&env, "0.1.0")
+    fn version(env: &Env) -> soroban_sdk::String {
+        soroban_sdk::String::from_str(env, "0.1.0")
     }
 
-    fn upgrade(env: Env, new_wasm_hash: BytesN<32>) {
-        Self::owner(&env).require_auth();
+    fn upgrade(env: &Env, new_wasm_hash: BytesN<32>) {
+        Self::owner(env).require_auth();
 
         env.deployer().update_current_contract_wasm(new_wasm_hash);
     }
diff --git a/packages/axelar-soroban-std/src/upgrade.rs b/packages/axelar-soroban-std/src/upgrade.rs
index f239e1b6..1f42ca8e 100644
--- a/packages/axelar-soroban-std/src/upgrade.rs
+++ b/packages/axelar-soroban-std/src/upgrade.rs
@@ -3,8 +3,8 @@ use soroban_sdk::{contractclient, BytesN, Env, String};
 #[contractclient(name = "UpgradeableClient")]
 pub trait UpgradeableInterface {
     /// Returns the current version of the contract.
-    fn version(env: Env) -> String;
+    fn version(env: &Env) -> String;
 
     /// Upgrades the contract to a new WASM hash.
-    fn upgrade(env: Env, new_wasm_hash: BytesN<32>);
+    fn upgrade(env: &Env, new_wasm_hash: BytesN<32>);
 }