diff --git a/crates/luaffi/src/lib.rs b/crates/luaffi/src/lib.rs
index fee204a..5e1fc92 100644
--- a/crates/luaffi/src/lib.rs
+++ b/crates/luaffi/src/lib.rs
@@ -129,7 +129,7 @@ fn cache_local(f: &mut Formatter, list: &[(&str, &str)]) -> fmt::Result {
 #[derive(Debug, Clone, Default)]
 pub struct Registry {
     types: HashSet<String>,
-    funcs: HashSet<String>,
+    decls: HashSet<String>,
     cdef: String,
     lua: String,
 }
@@ -146,16 +146,16 @@ impl Registry {
     pub fn include<T: Type>(&mut self) -> &mut Self {
         self.types
             .insert(T::name().to_string())
-            .then(|| T::build(&mut TypeBuilder::new::<T>(self)));
+            .then(|| T::build(&mut TypeBuilder::new(self)));
         self
     }
 
     pub fn declare<T: Type>(&mut self, name: impl Display) -> &mut Self {
         assert!(T::ty() != TypeType::Void, "cannot declare void type");
         self.include::<T>()
-            .funcs
-            .insert(name.to_string())
-            .then(|| writeln!(self.cdef, "{};", T::extern_cdecl(name)).unwrap());
+            .decls
+            .insert(T::extern_cdecl(&name).to_string())
+            .then(|| writeln!(self.cdef, "{};", T::extern_cdecl(&name)).unwrap());
         self
     }
 
@@ -184,7 +184,7 @@ impl Display for Registry {
         cache_local(f, CACHE_LIBS)?;
         cache_local(f, CACHE_LOCALS)?;
         writeln!(f, "{}", include_str!("./lib.lua"))?;
-        writeln!(f, "__cdef [[\n{}\n]];", self.cdef.trim())?;
+        writeln!(f, "__cdef [[\n{}\n]];", self.cdef.trim_end())?;
         write!(f, "{}", self.lua)
     }
 }
@@ -210,31 +210,23 @@ pub enum TypeType {
 
 #[derive(Debug)]
 pub struct TypeBuilder<'r> {
-    registry: &'r mut Registry,
+    reg: &'r mut Registry,
 }
 
 impl<'r> TypeBuilder<'r> {
-    fn new<T: Type>(registry: &'r mut Registry) -> Self {
-        let ct = T::name();
-        let cdecl = T::cdecl("");
-        writeln!(registry.lua, r#"__ct.{ct} = __typeof("{cdecl}");"#).unwrap();
-        Self { registry }
-    }
-
-    pub fn include<T: Type>(&mut self) -> &mut Self {
-        self.registry.include::<T>();
-        self
+    fn new(reg: &'r mut Registry) -> Self {
+        Self { reg }
     }
 
     pub fn cdef<T: Cdef>(&mut self) -> &mut Self {
-        let mut b = CdefBuilder::new::<T>(self.registry);
+        let mut b = CdefBuilder::new::<T>(self.reg);
         <T as Cdef>::build(&mut b);
         drop(b);
         self
     }
 
     pub fn metatype<T: Metatype>(&mut self) -> &mut Self {
-        let mut b = MetatypeBuilder::new::<T>(self.registry);
+        let mut b = MetatypeBuilder::new::<T>(self.reg);
         <T as Metatype>::build(&mut b);
         drop(b);
         self
@@ -251,16 +243,16 @@ pub unsafe trait Cdef: Type {
 
 #[derive(Debug)]
 pub struct CdefBuilder<'r> {
-    registry: &'r mut Registry,
+    reg: &'r mut Registry,
     cdef: String,
     align: usize,
     opaque: usize,
 }
 
 impl<'r> CdefBuilder<'r> {
-    fn new<T: Cdef>(registry: &'r mut Registry) -> Self {
+    fn new<T: Cdef>(reg: &'r mut Registry) -> Self {
         Self {
-            registry,
+            reg,
             cdef: format!("{} {{ ", T::cdecl("")),
             align: mem::align_of::<T>(),
             opaque: 0,
@@ -269,7 +261,7 @@ impl<'r> CdefBuilder<'r> {
 
     pub fn field<T: Type>(&mut self, name: impl Display) -> &mut Self {
         assert!(T::ty() != TypeType::Void, "cannot declare void field");
-        self.registry.include::<T>();
+        self.reg.include::<T>();
         self.field_raw(T::cdecl(name))
     }
 
@@ -303,14 +295,11 @@ impl<'r> CdefBuilder<'r> {
 impl<'r> Drop for CdefBuilder<'r> {
     fn drop(&mut self) {
         let Self {
-            registry,
-            cdef,
-            align,
-            ..
+            reg, cdef, align, ..
         } = self;
 
-        registry.cdef.push_str(cdef);
-        writeln!(registry.cdef, "}} __attribute__((aligned({align})));").unwrap();
+        reg.cdef.push_str(cdef);
+        writeln!(reg.cdef, "}} __attribute__((aligned({align})));").unwrap();
     }
 }
 
@@ -321,26 +310,34 @@ pub unsafe trait Metatype {
 
 #[derive(Debug)]
 pub struct MetatypeBuilder<'r> {
-    registry: &'r mut Registry,
+    reg: &'r mut Registry,
     ct: String,
     cdef: String,
     lua: String,
     lua_includes: Vec<&'static str>,
+    has_index: bool,
 }
 
 impl<'r> MetatypeBuilder<'r> {
-    fn new<T: Metatype>(registry: &'r mut Registry) -> Self {
+    fn new<T: Metatype>(reg: &'r mut Registry) -> Self {
+        // NOTE: this needs to be written first, because recursively included dependency types might
+        // need it
+        let ct = T::Target::name();
+        let cdecl = T::Target::cdecl("");
+        writeln!(reg.lua, r#"__ct.{ct} = __typeof("{cdecl}");"#).unwrap();
+
         Self {
-            registry,
+            reg,
             ct: T::Target::name().to_string(),
             cdef: String::new(),
-            lua: r#"do local __mt, __idx = {}, {}; __mt.__index = __idx; "#.into(),
+            lua: String::new(),
             lua_includes: vec![],
+            has_index: false,
         }
     }
 
     pub fn declare<T: Type>(&mut self, name: impl Display) -> &mut Self {
-        self.registry.declare::<T>(name);
+        self.reg.declare::<T>(name);
         self
     }
 
@@ -357,11 +354,13 @@ impl<'r> MetatypeBuilder<'r> {
         write!(self.lua, "__idx.{name} = ").unwrap();
         f(&mut MetatypeFunctionBuilder::new(self));
         writeln!(self.lua, ";").unwrap();
+        self.has_index = true;
         self
     }
 
     pub fn index_raw(&mut self, name: impl Display, value: impl Display) -> &mut Self {
         writeln!(self.lua, "__idx.{name} = {value};").unwrap();
+        self.has_index = true;
         self
     }
 
@@ -385,18 +384,27 @@ impl<'r> MetatypeBuilder<'r> {
 impl<'r> Drop for MetatypeBuilder<'r> {
     fn drop(&mut self) {
         let Self {
-            registry,
+            reg,
             ct,
             cdef,
             lua,
-            lua_includes: lua_postlude,
+            lua_includes,
+            has_index,
         } = self;
 
-        registry.cdef.push_str(cdef);
-        registry.lua.push_str(lua);
-        writeln!(registry.lua, r#"__metatype(__ct.{ct}, __mt); end;"#).unwrap();
-        for lua in lua_postlude {
-            writeln!(registry.lua, r#"do {lua} end;"#).unwrap();
+        write!(reg.lua, r#"do local __mt = {{}}; "#).unwrap();
+
+        if *has_index {
+            write!(reg.lua, r#"local __idx = {{}}; __mt.__index = __idx; "#).unwrap();
+        }
+
+        reg.cdef.push_str(cdef);
+        reg.lua.push_str(lua.trim_end());
+
+        writeln!(reg.lua, r#"__metatype(__ct.{ct}, __mt); end;"#).unwrap();
+
+        for lua in lua_includes {
+            writeln!(reg.lua, "do {}\nend;", lua.trim_end()).unwrap();
         }
     }
 }
@@ -471,7 +479,7 @@ impl<'r, 'm> MetatypeFunctionBuilder<'r, 'm> {
         );
 
         let Self {
-            metatype: MetatypeBuilder { registry, .. },
+            metatype: MetatypeBuilder { reg, .. },
             lparams,
             cparams,
             cargs,
@@ -480,7 +488,7 @@ impl<'r, 'm> MetatypeFunctionBuilder<'r, 'm> {
             ..
         } = self;
 
-        registry.include::<T::From>();
+        reg.include::<T::From>();
 
         (!lparams.is_empty()).then(|| lparams.push_str(", "));
         (!cparams.is_empty()).then(|| cparams.push_str(", "));
@@ -552,13 +560,7 @@ impl<'r, 'm> MetatypeFunctionBuilder<'r, 'm> {
 
     pub fn call<T: IntoFfi>(&mut self, func: impl Display) {
         let Self {
-            metatype:
-                MetatypeBuilder {
-                    registry,
-                    cdef,
-                    lua,
-                    ..
-                },
+            metatype: MetatypeBuilder { reg, cdef, lua, .. },
             lparams,
             cparams,
             cargs,
@@ -567,7 +569,7 @@ impl<'r, 'm> MetatypeFunctionBuilder<'r, 'm> {
             ..
         } = self;
 
-        registry.include::<T::Into>();
+        reg.include::<T::Into>();
         write!(lua, "function({lparams}) {prelude}").unwrap();
 
         match T::convention() {
@@ -812,7 +814,7 @@ macro_rules! impl_ptr {
             }
 
             fn build(b: &mut TypeBuilder) {
-                b.include::<T>();
+                b.reg.include::<T>();
             }
         }
     };
@@ -1009,7 +1011,7 @@ where
     }
 
     fn build(b: &mut TypeBuilder) {
-        b.include::<T>();
+        b.reg.include::<T>();
     }
 }
 
@@ -1039,7 +1041,7 @@ where
     }
 
     fn build(b: &mut TypeBuilder) {
-        b.include::<T>();
+        b.reg.include::<T>();
     }
 }
 
@@ -1103,8 +1105,8 @@ macro_rules! impl_externcfn {
             }
 
             fn build(b: &mut TypeBuilder) {
-                $(b.include::<$arg>();)*
-                b.include::<$ret>();
+                $(b.reg.include::<$arg>();)*
+                b.reg.include::<$ret>();
             }
         }
     };
diff --git a/crates/luaffi/src/option.rs b/crates/luaffi/src/option.rs
index 56865c0..99e5dfa 100644
--- a/crates/luaffi/src/option.rs
+++ b/crates/luaffi/src/option.rs
@@ -1,6 +1,6 @@
 use crate::{
     __internal::{disp, display, type_id},
-    Cdef, CdefBuilder, IntoFfi, KEEP_FN, Type, TypeBuilder, TypeType,
+    Cdef, CdefBuilder, IntoFfi, KEEP_FN, Metatype, MetatypeBuilder, Type, TypeBuilder, TypeType,
 };
 use std::{ffi::c_int, fmt::Display};
 
@@ -25,7 +25,7 @@ unsafe impl<T: Type + 'static> Type for lua_option<T> {
     }
 
     fn build(b: &mut TypeBuilder) {
-        b.cdef::<Self>();
+        b.cdef::<Self>().metatype::<Self>();
     }
 }
 
@@ -36,6 +36,11 @@ unsafe impl<T: Type + 'static> Cdef for lua_option<T> {
     }
 }
 
+unsafe impl<T: Type + 'static> Metatype for lua_option<T> {
+    type Target = Self;
+    fn build(_b: &mut MetatypeBuilder) {}
+}
+
 unsafe impl<T: IntoFfi<Into: 'static>> IntoFfi for Option<T> {
     type Into = lua_option<T::Into>;
 
diff --git a/crates/luaffi/src/result.rs b/crates/luaffi/src/result.rs
index 5d6e01f..f6e107d 100644
--- a/crates/luaffi/src/result.rs
+++ b/crates/luaffi/src/result.rs
@@ -1,6 +1,6 @@
 use crate::{
     __internal::{disp, display, type_id},
-    Cdef, CdefBuilder, IntoFfi, KEEP_FN, Type, TypeBuilder, TypeType,
+    Cdef, CdefBuilder, IntoFfi, KEEP_FN, Metatype, MetatypeBuilder, Type, TypeBuilder, TypeType,
     string::{DROP_BUFFER_FN, lua_buffer},
 };
 use std::{ffi::c_int, fmt::Display};
@@ -26,7 +26,7 @@ unsafe impl<T: Type + 'static> Type for lua_result<T> {
     }
 
     fn build(b: &mut TypeBuilder) {
-        b.cdef::<Self>();
+        b.cdef::<Self>().metatype::<Self>();
     }
 }
 
@@ -39,6 +39,11 @@ unsafe impl<T: Type + 'static> Cdef for lua_result<T> {
     }
 }
 
+unsafe impl<T: Type + 'static> Metatype for lua_result<T> {
+    type Target = Self;
+    fn build(_b: &mut MetatypeBuilder) {}
+}
+
 unsafe impl<T: IntoFfi<Into: 'static>, E: Display> IntoFfi for Result<T, E> {
     type Into = lua_result<T::Into>;