diff --git a/crates/primitives/src/genesis.rs b/crates/primitives/src/genesis.rs
index 4fd8752f58..8ae6bfce35 100644
--- a/crates/primitives/src/genesis.rs
+++ b/crates/primitives/src/genesis.rs
@@ -12,7 +12,7 @@ use serde::{Deserialize, Serialize};
 use triehash::sec_trie_root;
 
 /// The genesis block specification.
-#[derive(Clone, Debug, Default, Serialize, Deserialize)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq)]
 #[serde(rename_all = "camelCase", default)]
 pub struct Genesis {
     /// The genesis header nonce.
@@ -36,6 +36,60 @@ pub struct Genesis {
     pub alloc: HashMap<Address, GenesisAccount>,
 }
 
+impl Genesis {
+    /// Set the nonce.
+    pub fn with_nonce(mut self, nonce: u64) -> Self {
+        self.nonce = nonce;
+        self
+    }
+
+    /// Set the timestamp.
+    pub fn with_timestamp(mut self, timestamp: u64) -> Self {
+        self.timestamp = timestamp;
+        self
+    }
+
+    /// Set the extra data.
+    pub fn with_extra_data(mut self, extra_data: Bytes) -> Self {
+        self.extra_data = extra_data;
+        self
+    }
+
+    /// Set the gas limit.
+    pub fn with_gas_limit(mut self, gas_limit: u64) -> Self {
+        self.gas_limit = gas_limit;
+        self
+    }
+
+    /// Set the difficulty.
+    pub fn with_difficulty(mut self, difficulty: U256) -> Self {
+        self.difficulty = difficulty;
+        self
+    }
+
+    /// Set the mix hash of the header.
+    pub fn with_mix_hash(mut self, mix_hash: H256) -> Self {
+        self.mix_hash = mix_hash;
+        self
+    }
+
+    /// Set the coinbase address.
+    pub fn with_coinbase(mut self, address: Address) -> Self {
+        self.coinbase = address;
+        self
+    }
+
+    /// Add accounts to the genesis block. If the address is already present,
+    /// the account is updated.
+    pub fn extend_accounts(
+        mut self,
+        accounts: impl IntoIterator<Item = (Address, GenesisAccount)>,
+    ) -> Self {
+        self.alloc.extend(accounts);
+        self
+    }
+}
+
 /// An account in the state of the genesis block.
 #[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
 pub struct GenesisAccount {
@@ -65,6 +119,30 @@ impl GenesisAccount {
         len += KECCAK_EMPTY.length();
         len
     }
+
+    /// Set the nonce.
+    pub fn with_nonce(mut self, nonce: Option<u64>) -> Self {
+        self.nonce = nonce;
+        self
+    }
+
+    /// Set the balance.
+    pub fn with_balance(mut self, balance: U256) -> Self {
+        self.balance = balance;
+        self
+    }
+
+    /// Set the code.
+    pub fn with_code(mut self, code: Option<Bytes>) -> Self {
+        self.code = code;
+        self
+    }
+
+    /// Set the storage.
+    pub fn with_storage(mut self, storage: Option<HashMap<H256, H256>>) -> Self {
+        self.storage = storage;
+        self
+    }
 }
 
 impl Encodable for GenesisAccount {
@@ -110,3 +188,104 @@ impl From<EthersGenesisAccount> for GenesisAccount {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use hex_literal::hex;
+
+    #[test]
+    fn test_genesis() {
+        let default_genesis = Genesis::default();
+
+        let nonce = 999;
+        let timestamp = 12345;
+        let extra_data = Bytes::from(b"extra-data");
+        let gas_limit = 333333;
+        let difficulty = U256::from(9000);
+        let mix_hash =
+            hex!("74385b512f1e0e47100907efe2b00ac78df26acba6dd16b0772923068a5801a8").into();
+        let coinbase = hex!("265873b6faf3258b3ab0827805386a2a20ed040e").into();
+        // create dummy account
+        let first_address: Address = hex!("7618a8c597b89e01c66a1f662078992c52a30c9a").into();
+        let mut account = HashMap::default();
+        account.insert(first_address, GenesisAccount::default());
+
+        // check values updated
+        let custom_genesis = Genesis::default()
+            .with_nonce(nonce)
+            .with_timestamp(timestamp)
+            .with_extra_data(extra_data.clone())
+            .with_gas_limit(gas_limit)
+            .with_difficulty(difficulty)
+            .with_mix_hash(mix_hash)
+            .with_coinbase(coinbase)
+            .extend_accounts(account.clone());
+
+        assert_ne!(custom_genesis, default_genesis);
+        // check every field
+        assert_eq!(custom_genesis.nonce, nonce);
+        assert_eq!(custom_genesis.timestamp, timestamp);
+        assert_eq!(custom_genesis.extra_data, extra_data);
+        assert_eq!(custom_genesis.gas_limit, gas_limit);
+        assert_eq!(custom_genesis.difficulty, difficulty);
+        assert_eq!(custom_genesis.mix_hash, mix_hash);
+        assert_eq!(custom_genesis.coinbase, coinbase);
+        assert_eq!(custom_genesis.alloc, account.clone());
+
+        // update existing account
+        assert_eq!(custom_genesis.alloc.len(), 1);
+        let same_address = first_address;
+        let new_alloc_account = GenesisAccount {
+            nonce: Some(1),
+            balance: U256::from(1),
+            code: Some(Bytes::from(b"code")),
+            storage: Some(HashMap::default()),
+        };
+        let mut updated_account = HashMap::default();
+        updated_account.insert(same_address, new_alloc_account);
+        let custom_genesis = custom_genesis.extend_accounts(updated_account.clone());
+        assert_ne!(account, updated_account);
+        assert_eq!(custom_genesis.alloc.len(), 1);
+
+        // add second account
+        let different_address = hex!("94e0681e3073dd71cec54b53afe988f39078fd1a").into();
+        let more_accounts = HashMap::from([(different_address, GenesisAccount::default())]);
+        let custom_genesis = custom_genesis.extend_accounts(more_accounts);
+        assert_eq!(custom_genesis.alloc.len(), 2);
+
+        // ensure accounts are different
+        let first_account = custom_genesis.alloc.get(&first_address);
+        let second_account = custom_genesis.alloc.get(&different_address);
+        assert!(first_account.is_some());
+        assert!(second_account.is_some());
+        assert_ne!(first_account, second_account);
+    }
+
+    #[test]
+    fn test_genesis_account() {
+        let default_account = GenesisAccount::default();
+
+        let nonce = Some(1);
+        let balance = U256::from(33);
+        let code = Some(Bytes::from(b"code"));
+        let root = hex!("9474ddfcea39c5a690d2744103e39d1ff1b03d18db10fc147d970ad24699395a").into();
+        let value = hex!("58eb8294d9bb16832a9dabfcb270fff99ab8ee1d8764e4f3d9fdf59ec1dee469").into();
+        let mut map = HashMap::default();
+        map.insert(root, value);
+        let storage = Some(map);
+
+        let genesis_account = GenesisAccount::default()
+            .with_nonce(nonce)
+            .with_balance(balance)
+            .with_code(code.clone())
+            .with_storage(storage.clone());
+
+        assert_ne!(default_account, genesis_account);
+        // check every field
+        assert_eq!(genesis_account.nonce, nonce);
+        assert_eq!(genesis_account.balance, balance);
+        assert_eq!(genesis_account.code, code);
+        assert_eq!(genesis_account.storage, storage);
+    }
+}