diff --git a/crates/luaffi/src/internal.rs b/crates/luaffi/src/internal.rs
index 70e5cae..2adde20 100644
--- a/crates/luaffi/src/internal.rs
+++ b/crates/luaffi/src/internal.rs
@@ -9,12 +9,12 @@ use std::{
 #[allow(non_camel_case_types)]
 pub mod stub_types {
     pub struct any;
-    pub type nil = ();
+    pub struct nil;
     pub type boolean = bool;
-    pub type lightuserdata = *mut ();
-    pub type number = f64;
-    pub type integer = i64;
-    pub type string = &'static str;
+    pub struct lightuserdata;
+    pub struct number;
+    pub struct integer;
+    pub type string = String;
     pub struct table;
     pub struct function;
     pub struct userdata;
diff --git a/crates/luaffi_impl/src/metatype.rs b/crates/luaffi_impl/src/metatype.rs
index bf574e4..98bc5f3 100644
--- a/crates/luaffi_impl/src/metatype.rs
+++ b/crates/luaffi_impl/src/metatype.rs
@@ -763,13 +763,13 @@ fn inject_merged_drop(registry: &mut Registry, lua: Option<&LuaFunction>) -> Res
 
 fn document_ffi_function(func: &mut ImplItemFn) {
     func.attrs.insert(0, parse_quote!(#[doc =
-        r#"<span class="stab" title="This is a C/FFI function." style="float: right; font-weight: 500; margin-left: 3px; padding-left: 5px; padding-right: 5px;">FFI</span>"#
+        r#"<span class="stab" title="This function is implemented in Rust and called via FFI." style="float: right; background: #fff5d6; font-weight: 500; margin-left: 3px; padding-left: 5px; padding-right: 5px;">FFI</span>"#
     ]));
 }
 
 fn document_lua_function(func: &mut ImplItemFn) {
     func.attrs.insert(0, parse_quote!(#[doc =
-        r#"<span class="stab" title="This is a Lua function." style="float: right; font-weight: 500; margin-left: 3px; padding-left: 5px; padding-right: 5px;">Lua</span>"#
+        r#"<span class="stab" title="This function is implemented in Lua." style="float: right; background: #ebf5ff; font-weight: 500; margin-left: 3px; padding-left: 5px; padding-right: 5px;">Lua</span>"#
     ]));
 }
 
@@ -799,6 +799,10 @@ fn document_metamethod(func: &mut ImplItemFn, method: Metamethod) {
         _ => format!("This is a metamethod and cannot be called directly."),
     };
 
+    func.attrs.insert(0, parse_quote!(#[doc =
+        r#"<span class="stab" title="This function is a metamethod." style="float: right; background: #ebf5ff; margin-left: 3px; padding-left: 5px; padding-right: 5px;">Metamethod</span>"#
+    ]));
+
     func.attrs.push(parse_quote!(#[doc = ""]));
     func.attrs.push(parse_quote!(#[doc = #s]));
 }