diff --git a/crates/backend/src/typegen.rs b/crates/backend/src/typegen.rs
index 7b3b9da8..0bbd2e1f 100644
--- a/crates/backend/src/typegen.rs
+++ b/crates/backend/src/typegen.rs
@@ -7,7 +7,7 @@ use std::collections::HashMap;
 use once_cell::sync::Lazy;
 use syn::Type;
 
-#[derive(Default)]
+#[derive(Default, Debug)]
 pub struct TypeDef {
   pub kind: String,
   pub name: String,
@@ -149,6 +149,10 @@ pub fn ty_to_ts_type(ty: &Type, is_return_ty: bool) -> String {
           } else {
             ts_ty = Some(known_ty.to_owned());
           }
+        } else if let Some(t) = crate::typegen::r#struct::CLASS_STRUCTS
+          .with(|c| c.borrow_mut().get(rust_ty.as_str()).cloned())
+        {
+          ts_ty = Some(t);
         } else {
           // there should be runtime registered type in else
           ts_ty = Some(rust_ty);
@@ -157,7 +161,7 @@ pub fn ty_to_ts_type(ty: &Type, is_return_ty: bool) -> String {
 
       ts_ty.unwrap_or_else(|| "any".to_owned())
     }
-
+    Type::Group(g) => ty_to_ts_type(&g.elem, is_return_ty),
     _ => "any".to_owned(),
   }
 }
diff --git a/crates/backend/src/typegen/fn.rs b/crates/backend/src/typegen/fn.rs
index 9d7c719a..4c93b3e8 100644
--- a/crates/backend/src/typegen/fn.rs
+++ b/crates/backend/src/typegen/fn.rs
@@ -87,6 +87,11 @@ impl NapiFn {
   fn gen_ts_func_ret(&self) -> String {
     match self.kind {
       FnKind::Constructor | FnKind::Setter => "".to_owned(),
+      FnKind::Factory => self
+        .parent
+        .clone()
+        .map(|i| format!(": {}", i.to_string().to_case(Case::Pascal)))
+        .unwrap_or_else(|| "".to_owned()),
       _ => {
         let ret = if let Some(ret) = &self.ret {
           let ts_type = ty_to_ts_type(ret, true);
diff --git a/crates/backend/src/typegen/struct.rs b/crates/backend/src/typegen/struct.rs
index 7998e0a2..3790bf75 100644
--- a/crates/backend/src/typegen/struct.rs
+++ b/crates/backend/src/typegen/struct.rs
@@ -6,10 +6,15 @@ use crate::{ty_to_ts_type, NapiImpl, NapiStruct, NapiStructKind};
 
 thread_local! {
   pub(crate) static TASK_STRUCTS: RefCell<HashMap<String, String>> = Default::default();
+  pub(crate) static CLASS_STRUCTS: RefCell<HashMap<String, String>> = Default::default();
 }
 
 impl ToTypeDef for NapiStruct {
   fn to_type_def(&self) -> TypeDef {
+    CLASS_STRUCTS.with(|c| {
+      c.borrow_mut()
+        .insert(self.name.to_string(), self.js_name.clone());
+    });
     TypeDef {
       kind: String::from(if self.kind == NapiStructKind::Object {
         "interface"
diff --git a/crates/macro/src/parser/mod.rs b/crates/macro/src/parser/mod.rs
index 6708c032..de4da2f6 100644
--- a/crates/macro/src/parser/mod.rs
+++ b/crates/macro/src/parser/mod.rs
@@ -782,7 +782,7 @@ impl ConvertToAST for syn::ItemImpl {
           continue;
         }
 
-        if opts.constructor().is_some() {
+        if opts.constructor().is_some() || opts.factory().is_some() {
           struct_js_name = check_recorded_struct_for_impl(&struct_name, &opts)?;
         }
 
diff --git a/examples/napi/__test__/typegen.spec.ts.md b/examples/napi/__test__/typegen.spec.ts.md
index a1601ee9..9408013c 100644
--- a/examples/napi/__test__/typegen.spec.ts.md
+++ b/examples/napi/__test__/typegen.spec.ts.md
@@ -54,6 +54,13 @@ Generated by [AVA](https://avajs.dev).
       whoami(): string␊
       static getDogKind(): Kind␊
     }␊
+    export class Blake2BHasher {␊
+      ␊
+      static withKey(key: Blake2bKey): Blake2BHasher␊
+    }␊
+    export class Blake2BKey {␊
+      ␊
+    }␊
     export class ClassWithFactory {␊
       name: string␊
       static withName(name: string): ClassWithFactory␊
diff --git a/examples/napi/__test__/typegen.spec.ts.snap b/examples/napi/__test__/typegen.spec.ts.snap
index f7edba92..d3478adf 100644
Binary files a/examples/napi/__test__/typegen.spec.ts.snap and b/examples/napi/__test__/typegen.spec.ts.snap differ
diff --git a/examples/napi/index.d.ts b/examples/napi/index.d.ts
index 2f236609..c532a62e 100644
--- a/examples/napi/index.d.ts
+++ b/examples/napi/index.d.ts
@@ -43,6 +43,13 @@ export class Animal {
   set name(name: string)
   whoami(): string
   static getDogKind(): Kind
+}
+export class Blake2BHasher {
+  
+  static withKey(key: Blake2bKey): Blake2BHasher
+}
+export class Blake2BKey {
+  
 }
 export class ClassWithFactory {
   name: string
diff --git a/examples/napi/src/class.rs b/examples/napi/src/class.rs
index 9b05a683..7d6ef668 100644
--- a/examples/napi/src/class.rs
+++ b/examples/napi/src/class.rs
@@ -53,3 +53,25 @@ impl Animal {
     Kind::Dog
   }
 }
+
+/// Smoking test for type generation
+#[napi]
+#[repr(transparent)]
+pub struct Blake2bHasher(u32);
+
+#[napi]
+impl Blake2bHasher {
+  #[napi(factory)]
+  pub fn with_key(key: &Blake2bKey) -> Self {
+    Blake2bHasher(key.get_inner())
+  }
+}
+
+#[napi]
+pub struct Blake2bKey(u32);
+
+impl Blake2bKey {
+  fn get_inner(&self) -> u32 {
+    self.0
+  }
+}