diff --git a/crates/napi/Cargo.toml b/crates/napi/Cargo.toml
index d1990c7f..22f864db 100644
--- a/crates/napi/Cargo.toml
+++ b/crates/napi/Cargo.toml
@@ -28,6 +28,7 @@ deferred_trace = ["napi4"]
 error_anyhow = ["anyhow"]
 experimental = ["napi-sys/experimental"]
 full = ["latin1", "napi9", "async", "serde-json", "experimental", "chrono_date"]
+object_indexmap = ["indexmap"]
 latin1 = ["encoding_rs"]
 napi1 = []
 napi2 = ["napi1", "napi-sys/napi2"]
@@ -40,6 +41,7 @@ napi8 = ["napi7", "napi-sys/napi8"]
 napi9 = ["napi8", "napi-sys/napi9"]
 noop = []
 serde-json = ["serde", "serde_json"]
+serde-json-ordered = ["serde-json", "serde_json/preserve_order"]
 tokio_fs = ["tokio/fs"]
 tokio_full = ["tokio/full"]
 tokio_io_std = ["tokio/io-std"]
@@ -93,3 +95,7 @@ version = "1"
 [dependencies.serde_json]
 optional = true
 version = "1"
+
+[dependencies.indexmap]
+optional = true
+version = "2"
diff --git a/crates/napi/src/bindgen_runtime/js_values/map.rs b/crates/napi/src/bindgen_runtime/js_values/map.rs
index 1a7e8c28..4534da0e 100644
--- a/crates/napi/src/bindgen_runtime/js_values/map.rs
+++ b/crates/napi/src/bindgen_runtime/js_values/map.rs
@@ -1,6 +1,9 @@
-use std::collections::HashMap;
+use std::collections::{BTreeMap, HashMap};
 use std::hash::{BuildHasher, Hash};
 
+#[cfg(feature = "object_indexmap")]
+use indexmap::IndexMap;
+
 use crate::bindgen_prelude::{Env, Result, ToNapiValue, *};
 
 impl<K, V, S> TypeName for HashMap<K, V, S> {
@@ -49,3 +52,101 @@ where
     Ok(map)
   }
 }
+
+impl<K, V> TypeName for BTreeMap<K, V> {
+  fn type_name() -> &'static str {
+    "BTreeMap"
+  }
+
+  fn value_type() -> ValueType {
+    ValueType::Object
+  }
+}
+
+impl<K: From<String> + Ord, V: FromNapiValue> ValidateNapiValue for BTreeMap<K, V> {}
+
+impl<K, V> ToNapiValue for BTreeMap<K, V>
+where
+  K: AsRef<str>,
+  V: ToNapiValue,
+{
+  unsafe fn to_napi_value(raw_env: sys::napi_env, val: Self) -> Result<sys::napi_value> {
+    let env = Env::from(raw_env);
+    let mut obj = env.create_object()?;
+    for (k, v) in val.into_iter() {
+      obj.set(k.as_ref(), v)?;
+    }
+
+    unsafe { Object::to_napi_value(raw_env, obj) }
+  }
+}
+
+impl<K, V> FromNapiValue for BTreeMap<K, V>
+where
+  K: From<String> + Ord,
+  V: FromNapiValue,
+{
+  unsafe fn from_napi_value(env: sys::napi_env, napi_val: sys::napi_value) -> Result<Self> {
+    let obj = unsafe { Object::from_napi_value(env, napi_val)? };
+    let mut map = BTreeMap::default();
+    for key in Object::keys(&obj)?.into_iter() {
+      if let Some(val) = obj.get(&key)? {
+        map.insert(K::from(key), val);
+      }
+    }
+
+    Ok(map)
+  }
+}
+
+#[cfg(feature = "object_indexmap")]
+impl<K, V, S> TypeName for IndexMap<K, V, S> {
+  fn type_name() -> &'static str {
+    "IndexMap"
+  }
+
+  fn value_type() -> ValueType {
+    ValueType::Object
+  }
+}
+
+#[cfg(feature = "object_indexmap")]
+impl<K: From<String> + Hash + Eq, V: FromNapiValue> ValidateNapiValue for IndexMap<K, V> {}
+
+#[cfg(feature = "object_indexmap")]
+impl<K, V, S> ToNapiValue for IndexMap<K, V, S>
+where
+  K: AsRef<str>,
+  V: ToNapiValue,
+  S: Default + BuildHasher,
+{
+  unsafe fn to_napi_value(raw_env: sys::napi_env, val: Self) -> Result<sys::napi_value> {
+    let env = Env::from(raw_env);
+    let mut obj = env.create_object()?;
+    for (k, v) in val.into_iter() {
+      obj.set(k.as_ref(), v)?;
+    }
+
+    unsafe { Object::to_napi_value(raw_env, obj) }
+  }
+}
+
+#[cfg(feature = "object_indexmap")]
+impl<K, V, S> FromNapiValue for IndexMap<K, V, S>
+where
+  K: From<String> + Hash + Eq,
+  V: FromNapiValue,
+  S: Default + BuildHasher,
+{
+  unsafe fn from_napi_value(env: sys::napi_env, napi_val: sys::napi_value) -> Result<Self> {
+    let obj = unsafe { Object::from_napi_value(env, napi_val)? };
+    let mut map = IndexMap::default();
+    for key in Object::keys(&obj)?.into_iter() {
+      if let Some(val) = obj.get(&key)? {
+        map.insert(K::from(key), val);
+      }
+    }
+
+    Ok(map)
+  }
+}
diff --git a/examples/napi/Cargo.toml b/examples/napi/Cargo.toml
index 311e49a5..2a359cf4 100644
--- a/examples/napi/Cargo.toml
+++ b/examples/napi/Cargo.toml
@@ -19,6 +19,7 @@ napi-shared = { path = "../napi-shared" }
 serde = "1"
 serde_derive = "1"
 serde_json = "1"
+indexmap = "2"
 
 [target.'cfg(not(target_family = "wasm"))'.dependencies]
 napi = { path = "../../crates/napi", default-features = false, features = [
@@ -27,6 +28,7 @@ napi = { path = "../../crates/napi", default-features = false, features = [
   "experimental",
   "latin1",
   "chrono_date",
+  "object_indexmap",
   "tokio",
   "async",
   "tokio_rt",
@@ -43,6 +45,7 @@ napi = { path = "../../crates/napi", default-features = false, features = [
   "experimental",
   "latin1",
   "chrono_date",
+  "object_indexmap",
   "tokio",
   "async",
   "tokio_rt",
diff --git a/examples/napi/__tests__/__snapshots__/typegen.spec.ts.md b/examples/napi/__tests__/__snapshots__/typegen.spec.ts.md
index 3b6b9133..9c63b059 100644
--- a/examples/napi/__tests__/__snapshots__/typegen.spec.ts.md
+++ b/examples/napi/__tests__/__snapshots__/typegen.spec.ts.md
@@ -392,6 +392,8 @@ Generated by [AVA](https://avajs.dev).
     ␊
     export function fnReceivedAliased(s: AliasedStruct, e: ALIAS): void␊
     ␊
+    export function getBtreeMapping(): BTreeMap␊
+    ␊
     export function getBuffer(): Buffer␊
     ␊
     export function getCwd(callback: (arg0: string) => void): void␊
@@ -402,6 +404,8 @@ Generated by [AVA](https://avajs.dev).
     ␊
     export function getGlobal(): typeof global␊
     ␊
+    export function getIndexMapping(): IndexMap␊
+    ␊
     export function getMapping(): Record<string, number>␊
     ␊
     export function getModuleFileName(): string␊
@@ -425,6 +429,8 @@ Generated by [AVA](https://avajs.dev).
     ␊
     export function getWords(): Array<string>␊
     ␊
+    export function indexmapPassthrough(fixture: IndexMap): IndexMap␊
+    ␊
     /** default enum values are continuos i32s start from 0 */␊
     export const enum Kind {␊
       /** Barks */␊
@@ -544,6 +550,10 @@ Generated by [AVA](https://avajs.dev).
       name: string␊
     }␊
     ␊
+    export function sumBtreeMapping(nums: BTreeMap): number␊
+    ␊
+    export function sumIndexMapping(nums: IndexMap): number␊
+    ␊
     export function sumMapping(nums: Record<string, number>): number␊
     ␊
     export function sumNums(nums: Array<number>): number␊
diff --git a/examples/napi/__tests__/__snapshots__/typegen.spec.ts.snap b/examples/napi/__tests__/__snapshots__/typegen.spec.ts.snap
index 8c15e912..f74ab62b 100644
Binary files a/examples/napi/__tests__/__snapshots__/typegen.spec.ts.snap and b/examples/napi/__tests__/__snapshots__/typegen.spec.ts.snap differ
diff --git a/examples/napi/__tests__/values.spec.ts b/examples/napi/__tests__/values.spec.ts
index 4de2771b..7807e55c 100644
--- a/examples/napi/__tests__/values.spec.ts
+++ b/examples/napi/__tests__/values.spec.ts
@@ -34,6 +34,11 @@ const {
   sumNums,
   getMapping,
   sumMapping,
+  getBtreeMapping,
+  sumBtreeMapping,
+  getIndexMapping,
+  sumIndexMapping,
+  indexmapPassthrough,
   getCwd,
   Animal,
   Kind,
@@ -202,6 +207,11 @@ test('array', (t) => {
 test('map', (t) => {
   t.deepEqual(getMapping(), { a: 101, b: 102 })
   t.is(sumMapping({ a: 101, b: 102 }), 203)
+  t.deepEqual(getBtreeMapping(), { a: 101, b: 102 })
+  t.is(sumBtreeMapping({ a: 101, b: 102 }), 203)
+  t.deepEqual(getIndexMapping(), { a: 101, b: 102 })
+  t.is(sumIndexMapping({ a: 101, b: 102 }), 203)
+  t.deepEqual(indexmapPassthrough({ a: 101, b: 102 }), { a: 101, b: 102 })
 })
 
 test('enum', (t) => {
diff --git a/examples/napi/index.d.ts b/examples/napi/index.d.ts
index 72b926a1..8dd4e2f9 100644
--- a/examples/napi/index.d.ts
+++ b/examples/napi/index.d.ts
@@ -382,6 +382,8 @@ export function fibonacci(n: number): number
 
 export function fnReceivedAliased(s: AliasedStruct, e: ALIAS): void
 
+export function getBtreeMapping(): BTreeMap
+
 export function getBuffer(): Buffer
 
 export function getCwd(callback: (arg0: string) => void): void
@@ -392,6 +394,8 @@ export function getExternal(external: ExternalObject<number>): number
 
 export function getGlobal(): typeof global
 
+export function getIndexMapping(): IndexMap
+
 export function getMapping(): Record<string, number>
 
 export function getModuleFileName(): string
@@ -415,6 +419,8 @@ export function getUndefined(): void
 
 export function getWords(): Array<string>
 
+export function indexmapPassthrough(fixture: IndexMap): IndexMap
+
 /** default enum values are continuos i32s start from 0 */
 export const enum Kind {
   /** Barks */
@@ -534,6 +540,10 @@ export interface StrictObject {
   name: string
 }
 
+export function sumBtreeMapping(nums: BTreeMap): number
+
+export function sumIndexMapping(nums: IndexMap): number
+
 export function sumMapping(nums: Record<string, number>): number
 
 export function sumNums(nums: Array<number>): number
diff --git a/examples/napi/src/map.rs b/examples/napi/src/map.rs
index c4d0bd43..d2f659be 100644
--- a/examples/napi/src/map.rs
+++ b/examples/napi/src/map.rs
@@ -1,4 +1,6 @@
-use std::collections::HashMap;
+use std::collections::{BTreeMap, HashMap};
+
+use indexmap::IndexMap;
 
 #[napi]
 fn get_mapping() -> HashMap<String, u32> {
@@ -12,3 +14,34 @@ fn get_mapping() -> HashMap<String, u32> {
 fn sum_mapping(nums: HashMap<String, u32>) -> u32 {
   nums.into_values().sum()
 }
+
+#[napi]
+fn get_btree_mapping() -> BTreeMap<String, u32> {
+  let mut map = BTreeMap::new();
+  map.insert("a".to_string(), 101);
+  map.insert("b".to_string(), 102);
+  map
+}
+
+#[napi]
+fn sum_btree_mapping(nums: BTreeMap<String, u32>) -> u32 {
+  nums.into_values().sum()
+}
+
+#[napi]
+fn get_index_mapping() -> IndexMap<String, u32> {
+  let mut map = IndexMap::new();
+  map.insert("a".to_string(), 101);
+  map.insert("b".to_string(), 102);
+  map
+}
+
+#[napi]
+fn sum_index_mapping(nums: IndexMap<String, u32>) -> u32 {
+  nums.into_values().sum()
+}
+
+#[napi]
+fn indexmap_passthrough(fixture: IndexMap<String, u32>) -> IndexMap<String, u32> {
+  fixture
+}