diff --git a/bins/revme/src/statetest/runner.rs b/bins/revme/src/statetest/runner.rs
index 55c388796e..1a8f81ffa7 100644
--- a/bins/revme/src/statetest/runner.rs
+++ b/bins/revme/src/statetest/runner.rs
@@ -172,7 +172,7 @@ pub fn execute_test_suit(
         }
         let mut env = Env::default();
         // cfg env. SpecId is set down the road
-        env.cfg.chain_id = U256::from(1); // for mainnet
+        env.cfg.chain_id = 1; // for mainnet
 
         // block env
         env.block.number = unit.env.current_number;
diff --git a/crates/interpreter/src/instructions/host_env.rs b/crates/interpreter/src/instructions/host_env.rs
index e3d7d5fc6a..f666a59e83 100644
--- a/crates/interpreter/src/instructions/host_env.rs
+++ b/crates/interpreter/src/instructions/host_env.rs
@@ -1,3 +1,5 @@
+use revm_primitives::U256;
+
 use crate::{
     gas, interpreter::Interpreter, primitives::Spec, primitives::SpecId::*, Host, InstructionResult,
 };
@@ -6,7 +8,7 @@ pub fn chainid<SPEC: Spec>(interpreter: &mut Interpreter, host: &mut dyn Host) {
     // EIP-1344: ChainID opcode
     check!(interpreter, SPEC::enabled(ISTANBUL));
     gas!(interpreter, gas::BASE);
-    push!(interpreter, host.env().cfg.chain_id);
+    push!(interpreter, U256::from(host.env().cfg.chain_id));
 }
 
 pub fn coinbase(interpreter: &mut Interpreter, host: &mut dyn Host) {
diff --git a/crates/primitives/src/env.rs b/crates/primitives/src/env.rs
index d9e41ba308..99e4cfb949 100644
--- a/crates/primitives/src/env.rs
+++ b/crates/primitives/src/env.rs
@@ -80,7 +80,7 @@ pub enum CreateScheme {
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[non_exhaustive]
 pub struct CfgEnv {
-    pub chain_id: U256,
+    pub chain_id: u64,
     pub spec_id: SpecId,
     /// Bytecode that is created with CREATE/CREATE2 is by default analysed and jumptable is created.
     /// This is very beneficial for testing and speeds up execution of that bytecode if called multiple times.
@@ -188,7 +188,7 @@ pub enum AnalysisKind {
 impl Default for CfgEnv {
     fn default() -> CfgEnv {
         CfgEnv {
-            chain_id: U256::from(1),
+            chain_id: 1,
             spec_id: SpecId::LATEST,
             perf_analyse_created_bytecodes: Default::default(),
             limit_contract_code_size: None,
@@ -308,7 +308,7 @@ impl Env {
 
         // Check if the transaction's chain id is correct
         if let Some(tx_chain_id) = self.tx.chain_id {
-            if U256::from(tx_chain_id) != self.cfg.chain_id {
+            if tx_chain_id != self.cfg.chain_id {
                 return Err(InvalidTransaction::InvalidChainId);
             }
         }