diff --git a/Cargo.lock b/Cargo.lock
index d052250..014a784 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2405,6 +2405,7 @@ dependencies = [
  "futures",
  "futures-util",
  "glob",
+ "indexmap",
  "itertools 0.13.0",
  "rpassword",
  "rustyline 14.0.0",
diff --git a/Cargo.toml b/Cargo.toml
index 60b5321..1b1fe2b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -29,3 +29,4 @@ async-trait = "0.1.80"
 futures-util = "0.3.30"
 semver = "1.0.23"
 shellexpand = { version = "3.1.0", features = ["path"] }
+indexmap = "2.2.6"
diff --git a/src/interpreter/interpreter.rs b/src/interpreter/interpreter.rs
index 67beec6..60430ec 100644
--- a/src/interpreter/interpreter.rs
+++ b/src/interpreter/interpreter.rs
@@ -1,5 +1,4 @@
 use std::cmp::Ordering;
-use std::collections::BTreeMap;
 use std::ops::{Add, Div, Mul, Neg, Rem, Sub};
 use std::str::FromStr;
 
@@ -7,6 +6,7 @@ use alloy::hex::FromHex;
 use alloy::primitives::{Address, B256, I256, U256};
 use anyhow::{anyhow, bail, Result};
 use futures::future::{BoxFuture, FutureExt};
+use indexmap::IndexMap;
 use solang_parser::pt::{ContractPart, Expression, Statement};
 
 use crate::loaders::types::Project;
@@ -519,7 +519,7 @@ pub fn evaluate_expression(env: &mut Env, expr: Box<Expression>) -> BoxFuture<'_
                 } else {
                     bail!("expected variable, found {:?}", name_expr);
                 };
-                let mut fields = BTreeMap::new();
+                let mut fields = IndexMap::new();
                 for arg in args.iter() {
                     let value = evaluate_expression(env, Box::new(arg.expr.clone())).await?;
                     fields.insert(arg.name.name.clone(), value);
diff --git a/src/interpreter/types.rs b/src/interpreter/types.rs
index e2267fc..b40f29d 100644
--- a/src/interpreter/types.rs
+++ b/src/interpreter/types.rs
@@ -1,4 +1,4 @@
-use std::{collections::BTreeMap, fmt::Display};
+use std::fmt::Display;
 
 use alloy::{
     dyn_abi::DynSolType,
@@ -7,6 +7,7 @@ use alloy::{
     rpc::types::{Log, TransactionReceipt},
 };
 use anyhow::{bail, Result};
+use indexmap::IndexMap;
 use itertools::Itertools;
 
 use super::{
@@ -110,7 +111,7 @@ pub enum Type {
     String,
     Array(Box<Type>),
     FixedArray(Box<Type>, usize),
-    NamedTuple(String, BTreeMap<String, Type>),
+    NamedTuple(String, IndexMap<String, Type>),
     Tuple(Vec<Type>),
     Contract(ContractInfo),
     Transaction,
@@ -311,7 +312,7 @@ impl Type {
                 Ok(Value::FixBytes(B256::from_slice(&new_vector), *size))
             }
             (Type::NamedTuple(name, types_), Value::Tuple(values)) => {
-                let mut new_values = BTreeMap::new();
+                let mut new_values = IndexMap::new();
                 for (key, value) in types_.iter().zip(values.iter()) {
                     new_values.insert(key.0.clone(), key.1.cast(value)?);
                 }
diff --git a/src/interpreter/value.rs b/src/interpreter/value.rs
index fd6336a..0ce0ba8 100644
--- a/src/interpreter/value.rs
+++ b/src/interpreter/value.rs
@@ -4,9 +4,9 @@ use alloy::{
     primitives::{Address, B256, I256, U256},
 };
 use anyhow::{bail, Result};
+use indexmap::IndexMap;
 use itertools::Itertools;
 use std::{
-    collections::BTreeMap,
     fmt::{self, Display, Formatter},
     ops::{Add, Div, Mul, Rem, Sub},
 };
@@ -28,7 +28,7 @@ pub enum Value {
     Addr(Address),
     Contract(ContractInfo, Address),
     Tuple(Vec<Value>),
-    NamedTuple(String, BTreeMap<String, Value>),
+    NamedTuple(String, IndexMap<String, Value>),
     Array(Vec<Value>),
     TypeObject(Type),
     Transaction(B256),
@@ -40,7 +40,7 @@ fn _values_to_string(values: &[Value]) -> String {
     values.iter().map(|v| format!("{}", v)).join(", ")
 }
 
-fn _format_struct_fields(fields: &BTreeMap<String, Value>) -> String {
+fn _format_struct_fields(fields: &IndexMap<String, Value>) -> String {
     fields
         .iter()
         .map(|(k, v)| format!("{}: {}", k, v))
@@ -125,7 +125,7 @@ impl TryFrom<&Value> for alloy::dyn_abi::DynSolValue {
 
 impl From<alloy::rpc::types::Log> for Value {
     fn from(log: alloy::rpc::types::Log) -> Self {
-        let mut fields = BTreeMap::new();
+        let mut fields = IndexMap::new();
         fields.insert("address".to_string(), Value::Addr(log.address()));
         fields.insert(
             "topics".to_string(),
@@ -166,7 +166,7 @@ impl TryFrom<alloy::dyn_abi::DynSolValue> for Value {
                     .zip(tuple)
                     .map(|(k, dv)| Value::try_from(dv).map(|v| (k.clone(), v)))
                     .collect::<Result<Vec<_>>>()?;
-                Ok(Value::NamedTuple(name, BTreeMap::from_iter(vs)))
+                Ok(Value::NamedTuple(name, IndexMap::from_iter(vs)))
             }
             v => Err(anyhow::anyhow!("{:?} not supported", v)),
         }