diff --git a/src/typed/generator/luau_type_file_tests.rs b/src/typed/generator/luau_type_file_tests.rs
index c6e48d9..29520e0 100644
--- a/src/typed/generator/luau_type_file_tests.rs
+++ b/src/typed/generator/luau_type_file_tests.rs
@@ -2,7 +2,7 @@
 #![cfg(feature = "luau")]
 
 use crate::typed::{
-    Field, Func, Index, Param, Type, TypedClassBuilder,
+    Field, Func, Index, Param, Type, Typed, TypedClassBuilder, TypedUserData,
     function::Return,
     generator::{Definition, DefinitionBuilder, Definitions, Entry, LuauDefinitionFileGenerator},
 };
@@ -906,3 +906,75 @@ fn test_mismatch_enum_tuple_variants_flatten() {
         "export type Payload = \"None\" | { number | string } | { boolean }"
     );
 }
+
+/// Verify user data maps correctly
+/// This tests a custom struct TestUserData, including attrs, functions and methods
+/// It also test UserDataRef and UserDataRefMut in the function / method
+#[test]
+fn test_user_data() {
+    struct TestUserData {
+        attr: String,
+    }
+
+    impl mlua::UserData for TestUserData {}
+
+    impl Typed for TestUserData {
+        fn ty() -> Type {
+            Type::class(TypedClassBuilder::new::<Self>().build())
+        }
+
+        fn as_param() -> Type {
+            Type::named("TestUserData")
+        }
+
+        fn as_return() -> Type {
+            Self::as_param()
+        }
+    }
+
+    impl TypedUserData for TestUserData {
+        fn add_documentation<F: crate::typed::TypedDataDocumentation<Self>>(docs: &mut F) {
+            docs.add("class doc test");
+        }
+
+        fn add_fields<F: crate::typed::TypedDataFields<Self>>(fields: &mut F) {
+            fields.document("attr doc test");
+            fields.add_field_method_get("attr", |_, this| Ok(this.attr.clone()));
+        }
+
+        fn add_methods<T: crate::typed::TypedDataMethods<Self>>(methods: &mut T) {
+            methods.document("function doc test");
+            methods.add_function("from", |_, other: mlua::UserDataRef<Self>| {
+                Ok(Self {
+                    attr: other.attr.clone(),
+                })
+            });
+            methods.document("method doc test");
+            methods.add_method("to", |_, this, mut other: mlua::UserDataRefMut<Self>| {
+                (*other).attr = this.attr.clone();
+                Ok(())
+            });
+        }
+    }
+
+    let out = generate(single(
+        Definition::start().register_as("TestUserData", TestUserData::ty()),
+    ));
+    assert_eq!(
+        out.trim(),
+        r#"-- class doc test
+declare class TestUserData
+	-- attr doc test
+	attr: string
+	-- method doc test
+	function to(self, param1: TestUserData): ()
+end
+
+-- function doc test
+declare function TestUserData_from(param1: TestUserData): TestUserData
+
+declare TestUserData: {
+	from: typeof(TestUserData_from),
+}"#
+    );
+}
diff --git a/src/typed/generator/type_file_tests.rs b/src/typed/generator/type_file_tests.rs
index eb38604..433657e 100644
--- a/src/typed/generator/type_file_tests.rs
+++ b/src/typed/generator/type_file_tests.rs
@@ -1,7 +1,7 @@
 #![cfg(test)]
 
 use crate::typed::{
-    Index, Param, Type, TypedClassBuilder,
+    Index, Param, Type, Typed, TypedClassBuilder, TypedUserData,
     function::Return,
     generator::{Definition, DefinitionBuilder, DefinitionFileGenerator, Definitions, Entry},
 };
@@ -900,6 +900,79 @@ defaultColor = nil"#
     );
 }
 
+/// Verify user data maps correctly
+/// This tests a custom struct TestUserData, including attrs, functions and methods
+/// It also test UserDataRef and UserDataRefMut in the function / method
+#[test]
+fn test_user_data() {
+    struct TestUserData {
+        attr: String,
+    }
+    impl mlua::UserData for TestUserData {}
+
+    impl Typed for TestUserData {
+        fn ty() -> Type {
+            Type::class(TypedClassBuilder::new::<Self>().build())
+        }
+
+        fn as_param() -> Type {
+            Type::named("TestUserData")
+        }
+
+        fn as_return() -> Type {
+            Self::as_param()
+        }
+    }
+
+    impl TypedUserData for TestUserData {
+        fn add_documentation<F: crate::typed::TypedDataDocumentation<Self>>(docs: &mut F) {
+            docs.add("class doc test");
+        }
+
+        fn add_fields<F: crate::typed::TypedDataFields<Self>>(fields: &mut F) {
+            fields.document("attr doc test");
+            fields.add_field_method_get("attr", |_, this| Ok(this.attr.clone()));
+        }
+
+        fn add_methods<T: crate::typed::TypedDataMethods<Self>>(methods: &mut T) {
+            methods.document("function doc test");
+            methods.add_function("from", |_, other: mlua::UserDataRef<Self>| {
+                Ok(Self {
+                    attr: other.attr.clone(),
+                })
+            });
+            methods.document("method doc test");
+            methods.add_method("to", |_, this, mut other: mlua::UserDataRefMut<Self>| {
+                (*other).attr = this.attr.clone();
+                Ok(())
+            });
+        }
+    }
+
+    let out = generate(single(
+        Definition::start().register_as("TestUserData", TestUserData::ty()),
+    ));
+    assert_eq!(
+        out.trim(),
+        r#"--- @meta
+
+--- class doc test
+--- @class TestUserData
+--- attr doc test
+--- @field attr string
+local _CLASS_TestUserData_ = {
+	--- function doc test
+	--- @param param1 TestUserData
+	--- @return TestUserData
+	from = function(param1) end,
+	--- method doc test
+	--- @param self TestUserData
+	--- @param param1 TestUserData
+	to = function(self, param1) end,
+}"#
+    );
+}
+
 // ========================
 // lua-language-server validation tests
 // ========================
diff --git a/src/typed/mod.rs b/src/typed/mod.rs
index 63325c7..f23cbc4 100644
--- a/src/typed/mod.rs
+++ b/src/typed/mod.rs
@@ -16,7 +16,7 @@ use std::{sync::{Arc, Mutex}, cell::{Cell, RefCell}, rc::Rc};
 
 pub use function::{Param, Return, TypedFunction};
 
-use mlua::{IntoLua, MetaMethod, Value, Variadic};
+use mlua::{IntoLua, MetaMethod, UserDataRef, UserDataRefMut, Value, Variadic};
 
 /// Represents a lua table key
 ///
@@ -508,6 +508,34 @@ impl Typed for mlua::Value {
     }
 }
 
+impl<T: Typed> Typed for UserDataRef<T> {
+    fn ty() -> Type {
+        T::ty()
+    }
+
+    fn as_param() -> Type {
+        T::as_param()
+    }
+
+    fn as_return() -> Type {
+        T::as_return()
+    }
+}
+
+impl<T: Typed> Typed for UserDataRefMut<T> {
+    fn ty() -> Type {
+        T::ty()
+    }
+
+    fn as_param() -> Type {
+        T::as_param()
+    }
+
+    fn as_return() -> Type {
+        T::as_return()
+    }
+}
+
 impl<T: Typed> Typed for Variadic<T> {
     /// ...type
     fn ty() -> Type {