diff --git a/src/accounts/base.cairo b/src/accounts/base.cairo
index eaca705..921a38a 100644
--- a/src/accounts/base.cairo
+++ b/src/accounts/base.cairo
@@ -27,9 +27,9 @@ pub mod RosettaAccount {
     use core::num::traits::Zero;
     use core::panic_with_felt252;
     use starknet::{
-        ContractAddress, EthAddress, get_contract_address, get_caller_address, get_tx_info
+        ContractAddress, EthAddress, ClassHash, get_contract_address, get_caller_address, get_tx_info
     };
-    use starknet::syscalls::{call_contract_syscall};
+    use starknet::syscalls::{call_contract_syscall, replace_class_syscall};
     use starknet::storage::{StoragePointerReadAccess, StoragePointerWriteAccess};
     use rosettacontracts::accounts::utils::{is_valid_eth_signature, RosettanetSignature, RosettanetCall, RosettanetMulticall, prepare_multicall_context, validate_target_function, generate_tx_hash};
     use crate::rosettanet::{IRosettanetDispatcher, IRosettanetDispatcherTrait};
@@ -45,6 +45,7 @@ pub mod RosettaAccount {
 
     pub const TRANSFER_ENTRYPOINT: felt252 = 0x83afd3f4caedc6eebf44246fe54e38c95e3179a5ec9ea81740eca5b482d12e;
     pub const MULTICALL_SELECTOR: felt252 = 0xFFFFFFFF; // multicall eth selector
+    pub const UPGRADE_SELECTOR: felt252 = 0xFFFFFFFE; // upgrades contract
 
     #[storage]
     struct Storage {
@@ -71,14 +72,22 @@ pub mod RosettaAccount {
             let sn_target: ContractAddress = IRosettanetDispatcher { contract_address: self.registry.read() }.get_starknet_address(eth_target);
             assert(sn_target != starknet::contract_address_const::<0>(), 'target not registered');
 
-            // executes multicall
+            // Multicall or upgrade call
             if(call.to == self.ethereum_address.read()) {
                 // This is multicall
-                assert(*call.calldata.at(0) == MULTICALL_SELECTOR, 'wrong multicall selector');
-                assert(call.value == 0, 'multicall value not zero'); 
-                panic_with_felt252(Errors::UNIMPLEMENTED_FEATURE);
-                let context = prepare_multicall_context(call.calldata); // First calldata element removed inside this function
-                return self.execute_multicall(context);
+                let selector = *call.calldata.at(0);
+                if(selector == MULTICALL_SELECTOR) {
+                    assert(call.value == 0, 'multicall value not zero'); 
+                    panic_with_felt252(Errors::UNIMPLEMENTED_FEATURE);
+                    let context = prepare_multicall_context(call.calldata); // First calldata element removed inside this function
+                    return self.execute_multicall(context);
+                } else if(selector == UPGRADE_SELECTOR) {
+                    let latest_hash: ClassHash = IRosettanetDispatcher { contract_address: self.registry.read() }.latest_class();
+                    replace_class_syscall(latest_hash).unwrap();
+                    return array![array![latest_hash.into()].span()];
+                } else {
+                    panic_with_felt252(Errors::UNIMPLEMENTED_FEATURE);
+                }
             }
             
             // If value transfer, send STRK before calling contract
diff --git a/src/rosettanet.cairo b/src/rosettanet.cairo
index 698c723..6200e03 100644
--- a/src/rosettanet.cairo
+++ b/src/rosettanet.cairo
@@ -12,7 +12,7 @@ pub trait IRosettanet<TState> {
     fn get_starknet_address(self: @TState, eth_address: EthAddress) -> ContractAddress;
     fn get_ethereum_address(self: @TState, sn_address: ContractAddress) -> EthAddress;
     fn precalculate_starknet_account(self: @TState, eth_address: EthAddress) -> ContractAddress;
-    fn account_class(self: @TState) -> ClassHash;
+    fn latest_class(self: @TState) -> ClassHash;
     fn native_currency(self: @TState) -> ContractAddress;
     fn developer(self: @TState) -> ContractAddress;
 }
@@ -73,13 +73,18 @@ pub mod Rosettanet {
     struct Storage {
         sn_to_eth: Map<ContractAddress, EthAddress>,
         eth_to_sn: Map<EthAddress, ContractAddress>,
-        account_class: ClassHash,
+        latest_class: ClassHash,
+        // Accounts will always deployed with initial class, so we can always precalculate the addresses. 
+        // They may need to upgrade to the latest hash after deployment.
+        initial_class: ClassHash, 
         dev: ContractAddress,
         strk: ContractAddress
     }
 
     #[constructor]
-    fn constructor(ref self: ContractState, developer: ContractAddress, strk: ContractAddress) {
+    fn constructor(ref self: ContractState, account_class: ClassHash, developer: ContractAddress, strk: ContractAddress) {
+        self.initial_class.write(account_class);
+        self.latest_class.write(account_class);
         self.dev.write(developer);
         self.strk.write(strk);
 
@@ -106,7 +111,7 @@ pub mod Rosettanet {
             let eth_address_felt: felt252 = eth_address.into();
 
             let (account, _) = deploy_syscall(
-                self.account_class.read(), eth_address_felt, array![eth_address_felt, get_contract_address().into()].span(), true
+                self.initial_class.read(), eth_address_felt, array![eth_address_felt, get_contract_address().into()].span(), true
             )
                 .unwrap();
 
@@ -135,7 +140,7 @@ pub mod Rosettanet {
         fn set_account_class(ref self: ContractState, class: ClassHash) {
             assert(get_caller_address() == self.dev.read(), 'only dev');
 
-            self.account_class.write(class);
+            self.latest_class.write(class);
 
             self.emit(AccountClassChanged {changer: get_caller_address(), new_class: class});
         }
@@ -186,15 +191,15 @@ pub mod Rosettanet {
             let eth_address_felt: felt252 = eth_address.into();
             calculate_contract_address_from_deploy_syscall(
                 eth_address_felt,
-                self.account_class.read(),
+                self.initial_class.read(),
                 array![eth_address_felt, get_contract_address().into()].span(),
                 0.try_into().unwrap()
             )
         }
 
-        /// Returns current account class hash
-        fn account_class(self: @ContractState) -> ClassHash {
-            self.account_class.read()
+        /// Returns latest account class hash
+        fn latest_class(self: @ContractState) -> ClassHash {
+            self.latest_class.read()
         }
 
         /// Returns native currency address on current network