diff --git a/src/mlu/teal_data_methods.rs b/src/mlu/teal_data_methods.rs
index b5abb57..c422909 100644
--- a/src/mlu/teal_data_methods.rs
+++ b/src/mlu/teal_data_methods.rs
@@ -59,9 +59,9 @@ pub trait TealDataMethods<'lua, T: ToTypename> {
 
     #[cfg(feature = "mlua_async")]
     ///exposes an async function to lua
-    fn add_async_function<S: ?Sized, A, R, F, FR>(&mut self, name: &S, function: F)
+    fn add_async_function<S, A, R, F, FR>(&mut self, name: &S, function: F)
     where
-        S: AsRef<str>,
+        S: AsRef<str> + ?Sized,
         A: FromLuaMulti<'lua> + TealMultiValue,
         R: ToLuaMulti<'lua> + TealMultiValue,
         F: 'static + MaybeSend + Fn(&'lua Lua, A) -> FR,
diff --git a/src/mlu/user_data_wrapper.rs b/src/mlu/user_data_wrapper.rs
index 050e50b..fad4e51 100644
--- a/src/mlu/user_data_wrapper.rs
+++ b/src/mlu/user_data_wrapper.rs
@@ -248,9 +248,9 @@ where
 
     #[cfg(feature = "mlua_async")]
     #[inline(always)]
-    fn add_async_function<S: ?Sized, A, R, F, FR>(&mut self, name: &S, function: F)
+    fn add_async_function<S, A, R, F, FR>(&mut self, name: &S, function: F)
     where
-        S: AsRef<str>,
+        S: AsRef<str> + ?Sized,
         A: FromLuaMulti<'lua> + TealMultiValue,
         R: ToLuaMulti<'lua> + TealMultiValue,
         F: 'static + MaybeSend + Fn(&'lua Lua, A) -> FR,
diff --git a/src/rlu/named_parameters.rs b/src/rlu/named_parameters.rs
index e6e18fb..c79f623 100644
--- a/src/rlu/named_parameters.rs
+++ b/src/rlu/named_parameters.rs
@@ -68,9 +68,3 @@ macro_rules! rlua_create_named_parameters {
         }
     };
 }
-
-rlua_create_named_parameters!(
-    TestStruct with
-    field_1 : String,
-    field_2 : i64,
-);
diff --git a/src/type_generator.rs b/src/type_generator.rs
index e5d1644..dc49dab 100644
--- a/src/type_generator.rs
+++ b/src/type_generator.rs
@@ -821,9 +821,9 @@ where
     }
 
     #[cfg(feature = "mlua_async")]
-    fn add_async_function<S: ?Sized, A, R, F, FR>(&mut self, name: &S, _: F)
+    fn add_async_function<S, A, R, F, FR>(&mut self, name: &S, _: F)
     where
-        S: AsRef<str>,
+        S: AsRef<str> + ?Sized,
         A: FromLuaMultiM<'lua> + TealMultiValue,
         R: ToLuaMultiM<'lua> + TealMultiValue,
         F: 'static + MaybeSend + Fn(&'lua Lua, A) -> FR,