diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 717e02d1..a3afec52 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -34,7 +34,7 @@ jobs:
     - uses: actions/checkout@v2
       with:
         repository: "rust-blockchain/evm-tests"
-        submodules: true
+        submodules: recursive
     - name: Submodules
       run: |
         cd evm
diff --git a/benches/loop.rs b/benches/loop.rs
index 447c8a79..b9ca7ae7 100644
--- a/benches/loop.rs
+++ b/benches/loop.rs
@@ -19,6 +19,7 @@ fn run_loop_contract() {
 		block_gas_limit: Default::default(),
 		chain_id: U256::one(),
 		block_base_fee_per_gas: U256::zero(),
+		block_randomness: None,
 	};
 
 	let mut state = BTreeMap::new();
diff --git a/core/src/error.rs b/core/src/error.rs
index 510d6df4..9c6dd34e 100644
--- a/core/src/error.rs
+++ b/core/src/error.rs
@@ -127,6 +127,7 @@ pub enum ExitError {
 	/// Create init code exceeds limit (runtime).
 	#[cfg_attr(feature = "with-codec", codec(index = 7))]
 	CreateContractLimit,
+
 	/// Invalid opcode during execution or starting byte is 0xef. See [EIP-3541](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-3541.md).
 	#[cfg_attr(feature = "with-codec", codec(index = 15))]
 	InvalidCode(Opcode),
@@ -154,6 +155,11 @@ pub enum ExitError {
 	/// Other normal errors.
 	#[cfg_attr(feature = "with-codec", codec(index = 13))]
 	Other(Cow<'static, str>),
+
+	/// Nonce reached maximum value of 2^64-1
+	/// https://eips.ethereum.org/EIPS/eip-2681
+	#[cfg_attr(feature = "with-codec", codec(index = 14))]
+	MaxNonce,
 }
 
 impl From<ExitError> for ExitReason {
diff --git a/runtime/src/eval/mod.rs b/runtime/src/eval/mod.rs
index c65370fc..b2965335 100644
--- a/runtime/src/eval/mod.rs
+++ b/runtime/src/eval/mod.rs
@@ -40,7 +40,7 @@ pub fn eval<H: Handler>(state: &mut Runtime, opcode: Opcode, handler: &mut H) ->
 		Opcode::COINBASE => system::coinbase(state, handler),
 		Opcode::TIMESTAMP => system::timestamp(state, handler),
 		Opcode::NUMBER => system::number(state, handler),
-		Opcode::DIFFICULTY => system::difficulty(state, handler),
+		Opcode::DIFFICULTY => system::prevrandao(state, handler),
 		Opcode::GASLIMIT => system::gaslimit(state, handler),
 		Opcode::SLOAD => system::sload(state, handler),
 		Opcode::SSTORE => system::sstore(state, handler),
diff --git a/runtime/src/eval/system.rs b/runtime/src/eval/system.rs
index 57435543..e7ef5036 100644
--- a/runtime/src/eval/system.rs
+++ b/runtime/src/eval/system.rs
@@ -185,6 +185,15 @@ pub fn difficulty<H: Handler>(runtime: &mut Runtime, handler: &H) -> Control<H>
 	Control::Continue
 }
 
+pub fn prevrandao<H: Handler>(runtime: &mut Runtime, handler: &H) -> Control<H> {
+	if let Some(rand) = handler.block_randomness() {
+		push!(runtime, rand);
+		Control::Continue
+	} else {
+		difficulty(runtime, handler)
+	}
+}
+
 pub fn gaslimit<H: Handler>(runtime: &mut Runtime, handler: &H) -> Control<H> {
 	push_u256!(runtime, handler.block_gas_limit());
 	Control::Continue
diff --git a/runtime/src/handler.rs b/runtime/src/handler.rs
index e7e25182..31e894fb 100644
--- a/runtime/src/handler.rs
+++ b/runtime/src/handler.rs
@@ -54,6 +54,8 @@ pub trait Handler {
 	fn block_timestamp(&self) -> U256;
 	/// Get environmental block difficulty.
 	fn block_difficulty(&self) -> U256;
+	/// Get environmental block randomness.
+	fn block_randomness(&self) -> Option<H256>;
 	/// Get environmental gas limit.
 	fn block_gas_limit(&self) -> U256;
 	/// Environmental block base fee.
diff --git a/runtime/src/lib.rs b/runtime/src/lib.rs
index a5d3a54b..8809e58f 100644
--- a/runtime/src/lib.rs
+++ b/runtime/src/lib.rs
@@ -409,6 +409,11 @@ impl Config {
 		Self::config_with_derived_values(DerivedConfigInputs::london())
 	}
 
+	/// The Merge (Paris) hard fork configuration.
+	pub const fn merge() -> Config {
+		Self::config_with_derived_values(DerivedConfigInputs::merge())
+	}
+
 	/// Shanghai hard fork configuration.
 	pub const fn shanghai() -> Config {
 		Self::config_with_derived_values(DerivedConfigInputs::shanghai())
@@ -535,6 +540,20 @@ impl DerivedConfigInputs {
 		}
 	}
 
+	const fn merge() -> Self {
+		Self {
+			gas_storage_read_warm: 100,
+			gas_sload_cold: 2100,
+			gas_access_list_storage_key: 1900,
+			decrease_clears_refund: true,
+			has_base_fee: true,
+			has_push0: false,
+			disallow_executable_format: true,
+			warm_coinbase_address: false,
+			max_initcode_size: None,
+		}
+	}
+
 	const fn shanghai() -> Self {
 		Self {
 			gas_storage_read_warm: 100,
diff --git a/src/backend/memory.rs b/src/backend/memory.rs
index 7382a5e2..4910e628 100644
--- a/src/backend/memory.rs
+++ b/src/backend/memory.rs
@@ -31,6 +31,11 @@ pub struct MemoryVicinity {
 	pub block_gas_limit: U256,
 	/// Environmental base fee per gas.
 	pub block_base_fee_per_gas: U256,
+	/// Environmental randomness.
+	///
+	/// In Ethereum, this is the randomness beacon provided by the beacon
+	/// chain and is only enabled post Merge.
+	pub block_randomness: Option<H256>,
 }
 
 /// Account information of a memory backend.
@@ -42,7 +47,7 @@ pub struct MemoryVicinity {
 #[cfg_attr(feature = "with-serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct MemoryAccount {
 	/// Account nonce.
-	pub nonce: U256,
+	pub nonce: u64,
 	/// Account balance.
 	pub balance: U256,
 	/// Full account storage.
@@ -110,6 +115,9 @@ impl<'vicinity> Backend for MemoryBackend<'vicinity> {
 	fn block_difficulty(&self) -> U256 {
 		self.vicinity.block_difficulty
 	}
+	fn block_randomness(&self) -> Option<H256> {
+		self.vicinity.block_randomness
+	}
 	fn block_gas_limit(&self) -> U256 {
 		self.vicinity.block_gas_limit
 	}
@@ -202,8 +210,7 @@ impl<'vicinity> ApplyBackend for MemoryBackend<'vicinity> {
 						}
 
 						account.balance == U256::zero()
-							&& account.nonce == U256::zero()
-							&& account.code.is_empty()
+							&& account.nonce == 0 && account.code.is_empty()
 					};
 
 					if is_empty && delete_empty {
diff --git a/src/backend/mod.rs b/src/backend/mod.rs
index 1a503cbc..c442958c 100644
--- a/src/backend/mod.rs
+++ b/src/backend/mod.rs
@@ -20,7 +20,7 @@ pub struct Basic {
 	/// Account balance.
 	pub balance: U256,
 	/// Account nonce.
-	pub nonce: U256,
+	pub nonce: u64,
 }
 
 pub use ethereum::Log;
@@ -66,6 +66,8 @@ pub trait Backend {
 	fn block_timestamp(&self) -> U256;
 	/// Environmental block difficulty.
 	fn block_difficulty(&self) -> U256;
+	/// Get environmental block randomness.
+	fn block_randomness(&self) -> Option<H256>;
 	/// Environmental block gas limit.
 	fn block_gas_limit(&self) -> U256;
 	/// Environmental block base fee.
diff --git a/src/executor/stack/executor.rs b/src/executor/stack/executor.rs
index b50e68af..4f6f52cd 100644
--- a/src/executor/stack/executor.rs
+++ b/src/executor/stack/executor.rs
@@ -204,7 +204,7 @@ pub trait StackState<'config>: Backend {
 	fn is_cold(&self, address: H160) -> bool;
 	fn is_storage_cold(&self, address: H160, key: H256) -> bool;
 
-	fn inc_nonce(&mut self, address: H160);
+	fn inc_nonce(&mut self, address: H160) -> Result<(), ExitError>;
 	fn set_storage(&mut self, address: H160, key: H256, value: H256);
 	fn reset_storage(&mut self, address: H160);
 	fn log(&mut self, address: H160, topics: Vec<H256>, data: Vec<u8>);
@@ -304,7 +304,7 @@ impl<'config, 'precompiles, S: StackState<'config>, P: PrecompileSet>
 	/// Execute using Runtimes on the call_stack until it returns.
 	fn execute_with_call_stack(
 		&mut self,
-		call_stack: &mut Vec<TaggedRuntime>,
+		call_stack: &mut Vec<TaggedRuntime<'_>>,
 	) -> (ExitReason, Option<H160>, Vec<u8>) {
 		// This `interrupt_runtime` is used to pass the runtime obtained from the
 		// `Capture::Trap` branch in the match below back to the top of the call stack.
@@ -568,7 +568,9 @@ impl<'config, 'precompiles, S: StackState<'config>, P: PrecompileSet>
 			self.initialize_with_access_list(access_list);
 		}
 
-		self.state.inc_nonce(caller);
+		if let Err(e) = self.state.inc_nonce(caller) {
+			return (e.into(), Vec::new());
+		}
 
 		let context = Context {
 			caller,
@@ -616,7 +618,7 @@ impl<'config, 'precompiles, S: StackState<'config>, P: PrecompileSet>
 	}
 
 	/// Get account nonce.
-	pub fn nonce(&self, address: H160) -> U256 {
+	pub fn nonce(&self, address: H160) -> u64 {
 		self.state.basic(address).nonce
 	}
 
@@ -702,6 +704,10 @@ impl<'config, 'precompiles, S: StackState<'config>, P: PrecompileSet>
 			return Capture::Exit((ExitError::OutOfFund.into(), None, Vec::new()));
 		}
 
+		if let Err(e) = self.state.inc_nonce(caller) {
+			return Capture::Exit((e.into(), None, Vec::new()));
+		}
+
 		let after_gas = if take_l64 && self.config.call_l64_after_gas {
 			if self.config.estimate {
 				let initial_after_gas = self.state.metadata().gasometer.gas();
@@ -720,8 +726,6 @@ impl<'config, 'precompiles, S: StackState<'config>, P: PrecompileSet>
 		let gas_limit = min(after_gas, target_gas);
 		try_or_fail!(self.state.metadata_mut().gasometer.record_cost(gas_limit));
 
-		self.state.inc_nonce(caller);
-
 		self.enter_substate(gas_limit, false);
 
 		{
@@ -730,7 +734,7 @@ impl<'config, 'precompiles, S: StackState<'config>, P: PrecompileSet>
 				return Capture::Exit((ExitError::CreateCollision.into(), None, Vec::new()));
 			}
 
-			if self.nonce(address) > U256::zero() {
+			if self.nonce(address) > 0 {
 				let _ = self.exit_substate(StackExitKind::Failed);
 				return Capture::Exit((ExitError::CreateCollision.into(), None, Vec::new()));
 			}
@@ -757,7 +761,9 @@ impl<'config, 'precompiles, S: StackState<'config>, P: PrecompileSet>
 		}
 
 		if self.config.create_increase_nonce {
-			self.state.inc_nonce(address);
+			if let Err(e) = self.state.inc_nonce(address) {
+				return Capture::Exit((e.into(), None, Vec::new()));
+			}
 		}
 
 		let runtime = Runtime::new(
@@ -1108,6 +1114,9 @@ impl<'config, 'precompiles, S: StackState<'config>, P: PrecompileSet> Handler
 	fn block_difficulty(&self) -> U256 {
 		self.state.block_difficulty()
 	}
+	fn block_randomness(&self) -> Option<H256> {
+		self.state.block_randomness()
+	}
 	fn block_gas_limit(&self) -> U256 {
 		self.state.block_gas_limit()
 	}
diff --git a/src/executor/stack/memory.rs b/src/executor/stack/memory.rs
index ca04885c..d66c1033 100644
--- a/src/executor/stack/memory.rs
+++ b/src/executor/stack/memory.rs
@@ -198,14 +198,14 @@ impl<'config> MemoryStackSubstate<'config> {
 				return Some(false);
 			}
 
-			if account.basic.nonce != U256::zero() {
+			if account.basic.nonce != 0 {
 				return Some(false);
 			}
 
 			if let Some(code) = &account.code {
 				return Some(
 					account.basic.balance == U256::zero()
-						&& account.basic.nonce == U256::zero()
+						&& account.basic.nonce == 0
 						&& code.is_empty(),
 				);
 			}
@@ -301,8 +301,10 @@ impl<'config> MemoryStackSubstate<'config> {
 			.expect("New account was just inserted")
 	}
 
-	pub fn inc_nonce<B: Backend>(&mut self, address: H160, backend: &B) {
-		self.account_mut(address, backend).basic.nonce += U256::one();
+	pub fn inc_nonce<B: Backend>(&mut self, address: H160, backend: &B) -> Result<(), ExitError> {
+		let nonce = &mut self.account_mut(address, backend).basic.nonce;
+		*nonce = nonce.checked_add(1).ok_or(ExitError::MaxNonce)?;
+		Ok(())
 	}
 
 	pub fn set_storage(&mut self, address: H160, key: H256, value: H256) {
@@ -421,6 +423,9 @@ impl<'backend, 'config, B: Backend> Backend for MemoryStackState<'backend, 'conf
 	fn block_difficulty(&self) -> U256 {
 		self.backend.block_difficulty()
 	}
+	fn block_randomness(&self) -> Option<H256> {
+		self.backend.block_randomness()
+	}
 	fn block_gas_limit(&self) -> U256 {
 		self.backend.block_gas_limit()
 	}
@@ -494,7 +499,7 @@ impl<'backend, 'config, B: Backend> StackState<'config> for MemoryStackState<'ba
 		}
 
 		self.backend.basic(address).balance == U256::zero()
-			&& self.backend.basic(address).nonce == U256::zero()
+			&& self.backend.basic(address).nonce == 0
 			&& self.backend.code(address).len() == 0
 	}
 
@@ -510,8 +515,8 @@ impl<'backend, 'config, B: Backend> StackState<'config> for MemoryStackState<'ba
 		self.substate.is_storage_cold(address, key)
 	}
 
-	fn inc_nonce(&mut self, address: H160) {
-		self.substate.inc_nonce(address, self.backend);
+	fn inc_nonce(&mut self, address: H160) -> Result<(), ExitError> {
+		self.substate.inc_nonce(address, self.backend)
 	}
 
 	fn set_storage(&mut self, address: H160, key: H256, value: H256) {