diff --git a/derive/src/pymodule.rs b/derive/src/pymodule.rs
index 113c156d1..2b7a43d9a 100644
--- a/derive/src/pymodule.rs
+++ b/derive/src/pymodule.rs
@@ -290,7 +290,7 @@ impl ModuleItem for FunctionItem {
                     #doc
                     .into_function()
                     .with_module(vm.ctx.new_utf8_str(#module.to_owned()))
-                    .build(&vm.ctx)
+                    .into_ref(&vm.ctx)
             );
             quote! {
                 vm.__module_set_attr(&module, #py_name, #new_func).unwrap();
diff --git a/examples/mini_repl.rs b/examples/mini_repl.rs
index e3f23ed35..b24fe7fc2 100644
--- a/examples/mini_repl.rs
+++ b/examples/mini_repl.rs
@@ -43,7 +43,7 @@ fn run(vm: &vm::VirtualMachine) -> vm::PyResult<()> {
     // typing `quit()` is too long, let's make `on(False)` work instead.
     scope
         .globals
-        .set_item("on", vm.ctx.new_function("on", on), vm)?;
+        .set_item("on", vm.ctx.new_function("on", on).into(), vm)?;
 
     // let's include a fibonacci function, but let's be lazy and write it in Python
     add_python_function!(
diff --git a/stdlib/src/pyexpat.rs b/stdlib/src/pyexpat.rs
index cdb08be98..66c35e493 100644
--- a/stdlib/src/pyexpat.rs
+++ b/stdlib/src/pyexpat.rs
@@ -25,7 +25,7 @@ macro_rules! create_property {
             move |this: &PyExpatLikeXmlParser, func: PyObjectRef| *this.$element.write() = func,
         );
 
-        $attributes.insert($name.to_owned(), attr);
+        $attributes.insert($name.to_owned(), attr.into());
     };
 }
 
diff --git a/vm/src/builtins/builtinfunc.rs b/vm/src/builtins/builtinfunc.rs
index bed33c19b..c422e7da4 100644
--- a/vm/src/builtins/builtinfunc.rs
+++ b/vm/src/builtins/builtinfunc.rs
@@ -1,9 +1,9 @@
-use super::{pytype, PyClassMethod, PyStrRef, PyTypeRef};
+use super::{pytype, PyClassMethod, PyStr, PyStrRef, PyTypeRef};
 use crate::{
-    function::{FuncArgs, PyNativeFunc},
+    builtins::PyBoundMethod,
+    function::{FuncArgs, IntoPyNativeFunc, PyNativeFunc},
     slots::{Callable, SlotDescriptor},
-    PyClassImpl, PyContext, PyObject, PyObjectRef, PyRef, PyResult, PyValue, TypeProtocol,
-    VirtualMachine,
+    PyClassImpl, PyContext, PyObjectRef, PyRef, PyResult, PyValue, TypeProtocol, VirtualMachine,
 };
 use std::fmt;
 
@@ -21,34 +21,29 @@ impl PyNativeFuncDef {
             doc: None,
         }
     }
-}
 
-impl PyNativeFuncDef {
     pub fn with_doc(mut self, doc: String, ctx: &PyContext) -> Self {
-        self.doc = Some(ctx.new_stringref(doc));
+        self.doc = Some(PyStr::new_ref(doc, ctx));
         self
     }
 
     pub fn into_function(self) -> PyBuiltinFunction {
         self.into()
     }
-    pub fn build_function(self, ctx: &PyContext) -> PyObjectRef {
-        self.into_function().build(ctx)
+    pub fn build_function(self, ctx: &PyContext) -> PyRef<PyBuiltinFunction> {
+        self.into_function().into_ref(ctx)
     }
-    pub fn build_method(self, ctx: &PyContext, class: PyTypeRef) -> PyObjectRef {
-        PyObject::new(
+    pub fn build_method(self, ctx: &PyContext, class: PyTypeRef) -> PyRef<PyBuiltinMethod> {
+        PyRef::new_ref(
             PyBuiltinMethod { value: self, class },
             ctx.types.method_descriptor_type.clone(),
             None,
         )
     }
-    pub fn build_classmethod(self, ctx: &PyContext, class: PyTypeRef) -> PyObjectRef {
+    pub fn build_classmethod(self, ctx: &PyContext, class: PyTypeRef) -> PyRef<PyClassMethod> {
         // TODO: classmethod_descriptor
-        PyObject::new(
-            PyClassMethod::from(self.build_method(ctx, class)),
-            ctx.types.classmethod_type.clone(),
-            None,
-        )
+        let callable = self.build_method(ctx, class).into();
+        PyClassMethod::new_ref(callable, ctx)
     }
 }
 
@@ -85,8 +80,8 @@ impl PyBuiltinFunction {
         self
     }
 
-    pub fn build(self, ctx: &PyContext) -> PyObjectRef {
-        PyObject::new(
+    pub fn into_ref(self, ctx: &PyContext) -> PyRef<Self> {
+        PyRef::new_ref(
             self,
             ctx.types.builtin_function_or_method_type.clone(),
             None,
@@ -183,11 +178,12 @@ impl SlotDescriptor for PyBuiltinMethod {
             Ok(obj) => obj,
             Err(result) => return result,
         };
-        if vm.is_none(&obj) && !Self::_cls_is(&cls, &obj.class()) {
-            Ok(zelf.into())
+        let r = if vm.is_none(&obj) && !Self::_cls_is(&cls, &obj.class()) {
+            zelf.into()
         } else {
-            Ok(vm.ctx.new_bound_method(zelf.into(), obj))
-        }
+            PyBoundMethod::new_ref(obj, zelf.into(), &vm.ctx).into()
+        };
+        Ok(r)
     }
 }
 
@@ -197,6 +193,20 @@ impl Callable for PyBuiltinMethod {
     }
 }
 
+impl PyBuiltinMethod {
+    pub fn new_ref<F, FKind>(
+        name: impl Into<PyStr>,
+        class: PyTypeRef,
+        f: F,
+        ctx: &PyContext,
+    ) -> PyRef<Self>
+    where
+        F: IntoPyNativeFunc<FKind>,
+    {
+        ctx.make_funcdef(name, f).build_method(ctx, class)
+    }
+}
+
 #[pyimpl(with(SlotDescriptor, Callable), flags(METHOD_DESCR))]
 impl PyBuiltinMethod {
     #[pyproperty(magic)]
diff --git a/vm/src/builtins/bytearray.rs b/vm/src/builtins/bytearray.rs
index 306300924..2a34c129b 100644
--- a/vm/src/builtins/bytearray.rs
+++ b/vm/src/builtins/bytearray.rs
@@ -92,11 +92,6 @@ impl PyValue for PyByteArray {
 /// Fill bytearray class methods dictionary.
 pub(crate) fn init(context: &PyContext) {
     PyByteArray::extend_class(context, &context.types.bytearray_type);
-    let bytearray_type = &context.types.bytearray_type;
-    extend_class!(context, bytearray_type, {
-        "maketrans" => context.new_method("maketrans", bytearray_type.clone(), PyBytesInner::maketrans),
-    });
-
     PyByteArrayIterator::extend_class(context, &context.types.bytearray_iterator_type);
 }
 
@@ -227,6 +222,11 @@ impl PyByteArray {
         }
     }
 
+    #[pymethod]
+    fn maketrans(from: PyBytesInner, to: PyBytesInner, vm: &VirtualMachine) -> PyResult {
+        PyBytesInner::maketrans(from, to, vm)
+    }
+
     #[pymethod]
     fn pop(zelf: PyRef<Self>, index: OptionalArg<isize>, vm: &VirtualMachine) -> PyResult<u8> {
         let elements = &mut zelf.try_resizable(vm)?.elements;
diff --git a/vm/src/builtins/bytes.rs b/vm/src/builtins/bytes.rs
index 48fcb1119..694503d63 100644
--- a/vm/src/builtins/bytes.rs
+++ b/vm/src/builtins/bytes.rs
@@ -90,10 +90,6 @@ impl PyValue for PyBytes {
 
 pub(crate) fn init(context: &PyContext) {
     PyBytes::extend_class(context, &context.types.bytes_type);
-    let bytes_type = &context.types.bytes_type;
-    extend_class!(context, bytes_type, {
-        "maketrans" => context.new_method("maketrans", bytes_type.clone(), PyBytesInner::maketrans),
-    });
     PyBytesIterator::extend_class(context, &context.types.bytes_iterator_type);
 }
 
@@ -159,6 +155,11 @@ impl PyBytes {
         self.inner.contains(needle, vm)
     }
 
+    #[pymethod]
+    fn maketrans(from: PyBytesInner, to: PyBytesInner, vm: &VirtualMachine) -> PyResult {
+        PyBytesInner::maketrans(from, to, vm)
+    }
+
     #[pymethod(magic)]
     fn getitem(&self, needle: PyObjectRef, vm: &VirtualMachine) -> PyResult {
         self.inner.getitem("byte", needle, vm) // byte != Self::NAME
diff --git a/vm/src/builtins/classmethod.rs b/vm/src/builtins/classmethod.rs
index 058d9e704..58c3e37c6 100644
--- a/vm/src/builtins/classmethod.rs
+++ b/vm/src/builtins/classmethod.rs
@@ -1,7 +1,8 @@
 use super::PyTypeRef;
 use crate::{
+    builtins::PyBoundMethod,
     slots::{SlotConstructor, SlotDescriptor},
-    PyClassImpl, PyContext, PyObjectRef, PyResult, PyValue, TypeProtocol, VirtualMachine,
+    PyClassImpl, PyContext, PyObjectRef, PyRef, PyResult, PyValue, TypeProtocol, VirtualMachine,
 };
 
 /// classmethod(function) -> method
@@ -51,7 +52,7 @@ impl SlotDescriptor for PyClassMethod {
     ) -> PyResult {
         let (zelf, obj) = Self::_unwrap(zelf, obj, vm)?;
         let cls = cls.unwrap_or_else(|| obj.clone_class().into());
-        Ok(vm.ctx.new_bound_method(zelf.callable.clone(), cls))
+        Ok(PyBoundMethod::new_ref(cls, zelf.callable.clone(), &vm.ctx).into())
     }
 }
 
@@ -63,6 +64,12 @@ impl SlotConstructor for PyClassMethod {
     }
 }
 
+impl PyClassMethod {
+    pub fn new_ref(callable: PyObjectRef, ctx: &PyContext) -> PyRef<Self> {
+        PyRef::new_ref(Self { callable }, ctx.types.classmethod_type.clone(), None)
+    }
+}
+
 #[pyimpl(with(SlotDescriptor, SlotConstructor), flags(BASETYPE, HAS_DICT))]
 impl PyClassMethod {
     #[pyproperty(magic)]
diff --git a/vm/src/builtins/function.rs b/vm/src/builtins/function.rs
index fb282803a..a234b5782 100644
--- a/vm/src/builtins/function.rs
+++ b/vm/src/builtins/function.rs
@@ -408,7 +408,7 @@ impl SlotDescriptor for PyFunction {
         let obj = if vm.is_none(&obj) && !Self::_cls_is(&cls, &obj.class()) {
             zelf.into()
         } else {
-            vm.ctx.new_bound_method(zelf.into(), obj)
+            PyBoundMethod::new_ref(obj, zelf.into(), &vm.ctx).into()
         };
         Ok(obj)
     }
@@ -423,9 +423,8 @@ impl Callable for PyFunction {
 #[pyclass(module = false, name = "method")]
 #[derive(Debug)]
 pub struct PyBoundMethod {
-    // TODO: these shouldn't be public
     object: PyObjectRef,
-    pub function: PyObjectRef,
+    function: PyObjectRef,
 }
 
 impl Callable for PyBoundMethod {
@@ -480,15 +479,25 @@ impl SlotConstructor for PyBoundMethod {
     }
 }
 
+impl PyBoundMethod {
+    fn new(object: PyObjectRef, function: PyObjectRef) -> Self {
+        PyBoundMethod { object, function }
+    }
+
+    pub fn new_ref(object: PyObjectRef, function: PyObjectRef, ctx: &PyContext) -> PyRef<Self> {
+        PyRef::new_ref(
+            Self::new(object, function),
+            ctx.types.bound_method_type.clone(),
+            None,
+        )
+    }
+}
+
 #[pyimpl(
     with(Callable, Comparable, SlotGetattro, SlotConstructor),
     flags(HAS_DICT)
 )]
 impl PyBoundMethod {
-    pub fn new(object: PyObjectRef, function: PyObjectRef) -> Self {
-        PyBoundMethod { object, function }
-    }
-
     #[pymethod(magic)]
     fn repr(&self, vm: &VirtualMachine) -> PyResult<String> {
         let funcname =
diff --git a/vm/src/builtins/pytype.rs b/vm/src/builtins/pytype.rs
index c56fa05e2..05651c766 100644
--- a/vm/src/builtins/pytype.rs
+++ b/vm/src/builtins/pytype.rs
@@ -595,12 +595,14 @@ impl PyType {
         if !attributes.contains_key("__dict__") {
             attributes.insert(
                 "__dict__".to_owned(),
-                vm.ctx.new_getset(
-                    "__dict__",
-                    vm.ctx.types.object_type.clone(),
-                    subtype_get_dict,
-                    subtype_set_dict,
-                ),
+                vm.ctx
+                    .new_getset(
+                        "__dict__",
+                        vm.ctx.types.object_type.clone(),
+                        subtype_get_dict,
+                        subtype_set_dict,
+                    )
+                    .into(),
             );
         }
 
diff --git a/vm/src/builtins/staticmethod.rs b/vm/src/builtins/staticmethod.rs
index a4c644995..db134098f 100644
--- a/vm/src/builtins/staticmethod.rs
+++ b/vm/src/builtins/staticmethod.rs
@@ -1,5 +1,6 @@
 use super::{PyStr, PyTypeRef};
 use crate::{
+    builtins::builtinfunc::PyBuiltinMethod,
     function::IntoPyNativeFunc,
     slots::{SlotConstructor, SlotDescriptor},
     PyClassImpl, PyContext, PyObjectRef, PyRef, PyResult, PyValue, VirtualMachine,
@@ -53,7 +54,7 @@ impl PyStaticMethod {
     where
         F: IntoPyNativeFunc<FKind>,
     {
-        let callable = ctx.new_method(name, class, f);
+        let callable = PyBuiltinMethod::new_ref(name, class, f, ctx).into();
         PyRef::new_ref(Self { callable }, ctx.types.staticmethod_type.clone(), None)
     }
 }
diff --git a/vm/src/codecs.rs b/vm/src/codecs.rs
index 15c30afc4..7d1fbbfa2 100644
--- a/vm/src/codecs.rs
+++ b/vm/src/codecs.rs
@@ -173,7 +173,7 @@ impl CodecsRegistry {
             ),
         ];
         let errors = std::array::IntoIter::new(errors)
-            .map(|(name, f)| (name.to_owned(), f))
+            .map(|(name, f)| (name.to_owned(), f.into()))
             .collect();
         let inner = RegistryInner {
             search_path: Vec::new(),
diff --git a/vm/src/macros.rs b/vm/src/macros.rs
index a653e960d..30d45003d 100644
--- a/vm/src/macros.rs
+++ b/vm/src/macros.rs
@@ -225,7 +225,7 @@ macro_rules! named_function {
             )
             .into_function()
             .with_module(ctx.new_utf8_str(stringify!($module).to_owned()))
-            .build(ctx)
+            .into_ref(ctx)
         }
     }};
 }
diff --git a/vm/src/pyobject.rs b/vm/src/pyobject.rs
index ad39adf29..9233acb1a 100644
--- a/vm/src/pyobject.rs
+++ b/vm/src/pyobject.rs
@@ -6,7 +6,7 @@ use crate::common::{
 pub use crate::pyobjectrc::{PyObject, PyObjectRef, PyObjectWeak, PyObjectWrap, PyRef, PyWeakRef};
 use crate::{
     builtins::{
-        builtinfunc::PyNativeFuncDef,
+        builtinfunc::{PyBuiltinFunction, PyBuiltinMethod, PyNativeFuncDef},
         bytearray, bytes,
         code::{self, PyCode},
         getset::{IntoPyGetterFunc, IntoPySetterFunc, PyGetSet},
@@ -249,10 +249,6 @@ impl PyContext {
         create_type_with_slots(name, &self.types.type_type, base, slots)
     }
 
-    pub(crate) fn new_stringref(&self, s: String) -> pystr::PyStrRef {
-        PyRef::new_ref(pystr::PyStr::from(s), self.types.str_type.clone(), None)
-    }
-
     #[inline]
     pub fn make_funcdef<F, FKind>(&self, name: impl Into<PyStr>, f: F) -> PyNativeFuncDef
     where
@@ -261,7 +257,8 @@ impl PyContext {
         PyNativeFuncDef::new(f.into_func(), PyStr::new_ref(name, self))
     }
 
-    pub fn new_function<F, FKind>(&self, name: impl Into<PyStr>, f: F) -> PyObjectRef
+    // #[deprecated]
+    pub fn new_function<F, FKind>(&self, name: impl Into<PyStr>, f: F) -> PyRef<PyBuiltinFunction>
     where
         F: IntoPyNativeFunc<FKind>,
     {
@@ -273,23 +270,11 @@ impl PyContext {
         name: impl Into<PyStr>,
         class: PyTypeRef,
         f: F,
-    ) -> PyObjectRef
+    ) -> PyRef<PyBuiltinMethod>
     where
         F: IntoPyNativeFunc<FKind>,
     {
-        self.make_funcdef(name, f).build_method(self, class)
-    }
-
-    pub fn new_classmethod<F, FKind>(
-        &self,
-        name: impl Into<PyStr>,
-        class: PyTypeRef,
-        f: F,
-    ) -> PyObjectRef
-    where
-        F: IntoPyNativeFunc<FKind>,
-    {
-        self.make_funcdef(name, f).build_classmethod(self, class)
+        PyBuiltinMethod::new_ref(name, class, f, self)
     }
 
     pub fn new_readonly_getset<F, T>(
@@ -297,11 +282,11 @@ impl PyContext {
         name: impl Into<String>,
         class: PyTypeRef,
         f: F,
-    ) -> PyObjectRef
+    ) -> PyRef<PyGetSet>
     where
         F: IntoPyGetterFunc<T>,
     {
-        PyObject::new(
+        PyRef::new_ref(
             PyGetSet::new(name.into(), class).with_get(f),
             self.types.getset_type.clone(),
             None,
@@ -314,12 +299,12 @@ impl PyContext {
         class: PyTypeRef,
         g: G,
         s: S,
-    ) -> PyObjectRef
+    ) -> PyRef<PyGetSet>
     where
         G: IntoPyGetterFunc<T>,
         S: IntoPySetterFunc<U>,
     {
-        PyObject::new(
+        PyRef::new_ref(
             PyGetSet::new(name.into(), class).with_get(g).with_set(s),
             self.types.getset_type.clone(),
             None,
@@ -333,14 +318,6 @@ impl PyContext {
         PyRef::new_ref(PyCode::new(code), self.types.code_type.clone(), None)
     }
 
-    pub fn new_bound_method(&self, function: PyObjectRef, object: PyObjectRef) -> PyObjectRef {
-        PyObject::new(
-            PyBoundMethod::new(object, function),
-            self.types.bound_method_type.clone(),
-            None,
-        )
-    }
-
     pub fn new_base_object(&self, class: PyTypeRef, dict: Option<PyDictRef>) -> PyObjectRef {
         PyObject::new(object::PyBaseObject, class, dict)
     }
@@ -960,7 +937,9 @@ pub trait PyClassImpl: PyClassDef {
             class.set_str_attr("__module__", ctx.new_utf8_str(module_name));
         }
         if class.slots.new.load().is_some() {
-            let bound = ctx.new_bound_method(ctx.slot_new_wrapper.clone(), class.clone().into());
+            let bound: PyObjectRef =
+                PyBoundMethod::new_ref(class.clone().into(), ctx.slot_new_wrapper.clone(), ctx)
+                    .into();
             class.set_str_attr("__new__", bound);
         }
     }
diff --git a/wasm/lib/src/convert.rs b/wasm/lib/src/convert.rs
index 450f46542..3f1035100 100644
--- a/wasm/lib/src/convert.rs
+++ b/wasm/lib/src/convert.rs
@@ -215,24 +215,26 @@ pub fn js_to_py(vm: &VirtualMachine, js_val: JsValue) -> PyObjectRef {
         }
     } else if js_val.is_function() {
         let func = js_sys::Function::from(js_val);
-        vm.ctx.new_function(
-            func.name(),
-            move |args: FuncArgs, vm: &VirtualMachine| -> PyResult {
-                let this = Object::new();
-                for (k, v) in args.kwargs {
-                    Reflect::set(&this, &k.into(), &py_to_js(vm, v))
-                        .expect("property to be settable");
-                }
-                let js_args = args
-                    .args
-                    .into_iter()
-                    .map(|v| py_to_js(vm, v))
-                    .collect::<Array>();
-                func.apply(&this, &js_args)
-                    .map(|val| js_to_py(vm, val))
-                    .map_err(|err| js_err_to_py_err(vm, &err))
-            },
-        )
+        vm.ctx
+            .new_function(
+                String::from(func.name()),
+                move |args: FuncArgs, vm: &VirtualMachine| -> PyResult {
+                    let this = Object::new();
+                    for (k, v) in args.kwargs {
+                        Reflect::set(&this, &k.into(), &py_to_js(vm, v))
+                            .expect("property to be settable");
+                    }
+                    let js_args = args
+                        .args
+                        .into_iter()
+                        .map(|v| py_to_js(vm, v))
+                        .collect::<Array>();
+                    func.apply(&this, &js_args)
+                        .map(|val| js_to_py(vm, val))
+                        .map_err(|err| js_err_to_py_err(vm, &err))
+                },
+            )
+            .into()
     } else if let Some(err) = js_val.dyn_ref::<js_sys::Error>() {
         js_err_to_py_err(vm, err).into()
     } else if js_val.is_undefined() {