diff --git a/vm/src/obj/objenumerate.rs b/vm/src/obj/objenumerate.rs
index a1903aea4..5637a5879 100644
--- a/vm/src/obj/objenumerate.rs
+++ b/vm/src/obj/objenumerate.rs
@@ -26,27 +26,28 @@ impl PyValue for PyEnumerate {
     }
 }
 
-fn enumerate_new(
-    cls: PyClassRef,
-    iterable: PyObjectRef,
-    start: OptionalArg<PyIntRef>,
-    vm: &VirtualMachine,
-) -> PyResult<PyEnumerateRef> {
-    let counter = match start {
-        OptionalArg::Present(start) => start.as_bigint().clone(),
-        OptionalArg::Missing => BigInt::zero(),
-    };
-
-    let iterator = objiter::get_iter(vm, &iterable)?;
-    PyEnumerate {
-        counter: RefCell::new(counter.clone()),
-        iterator,
-    }
-    .into_ref_with_type(vm, cls)
-}
-
 #[pyimpl]
 impl PyEnumerate {
+    #[pyslot(new)]
+    fn tp_new(
+        cls: PyClassRef,
+        iterable: PyObjectRef,
+        start: OptionalArg<PyIntRef>,
+        vm: &VirtualMachine,
+    ) -> PyResult<PyEnumerateRef> {
+        let counter = match start {
+            OptionalArg::Present(start) => start.as_bigint().clone(),
+            OptionalArg::Missing => BigInt::zero(),
+        };
+
+        let iterator = objiter::get_iter(vm, &iterable)?;
+        PyEnumerate {
+            counter: RefCell::new(counter.clone()),
+            iterator,
+        }
+        .into_ref_with_type(vm, cls)
+    }
+
     #[pymethod(name = "__next__")]
     fn next(&self, vm: &VirtualMachine) -> PyResult {
         let iterator = &self.iterator;
@@ -69,7 +70,4 @@ impl PyEnumerate {
 
 pub fn init(context: &PyContext) {
     PyEnumerate::extend_class(context, &context.types.enumerate_type);
-    extend_class!(context, &context.types.enumerate_type, {
-        (slot new) => enumerate_new,
-    });
 }
diff --git a/vm/src/obj/objfilter.rs b/vm/src/obj/objfilter.rs
index 1e2222517..6f7e2c6d4 100644
--- a/vm/src/obj/objfilter.rs
+++ b/vm/src/obj/objfilter.rs
@@ -24,23 +24,24 @@ impl PyValue for PyFilter {
     }
 }
 
-fn filter_new(
-    cls: PyClassRef,
-    function: PyObjectRef,
-    iterable: PyObjectRef,
-    vm: &VirtualMachine,
-) -> PyResult<PyFilterRef> {
-    let iterator = objiter::get_iter(vm, &iterable)?;
-
-    PyFilter {
-        predicate: function.clone(),
-        iterator,
-    }
-    .into_ref_with_type(vm, cls)
-}
-
 #[pyimpl]
 impl PyFilter {
+    #[pyslot(new)]
+    fn tp_new(
+        cls: PyClassRef,
+        function: PyObjectRef,
+        iterable: PyObjectRef,
+        vm: &VirtualMachine,
+    ) -> PyResult<PyFilterRef> {
+        let iterator = objiter::get_iter(vm, &iterable)?;
+
+        PyFilter {
+            predicate: function.clone(),
+            iterator,
+        }
+        .into_ref_with_type(vm, cls)
+    }
+
     #[pymethod(name = "__next__")]
     fn next(&self, vm: &VirtualMachine) -> PyResult {
         let predicate = &self.predicate;
@@ -68,7 +69,4 @@ impl PyFilter {
 
 pub fn init(context: &PyContext) {
     PyFilter::extend_class(context, &context.types.filter_type);
-    extend_class!(context, &context.types.filter_type, {
-        (slot new) => filter_new,
-    });
 }
diff --git a/vm/src/obj/objint.rs b/vm/src/obj/objint.rs
index 078496eda..43506b58d 100644
--- a/vm/src/obj/objint.rs
+++ b/vm/src/obj/objint.rs
@@ -181,6 +181,11 @@ fn inner_rshift(int1: &PyInt, int2: &PyInt, vm: &VirtualMachine) -> PyResult {
 
 #[pyimpl]
 impl PyInt {
+    #[pyslot(new)]
+    fn tp_new(cls: PyClassRef, options: IntOptions, vm: &VirtualMachine) -> PyResult<PyIntRef> {
+        PyInt::new(options.get_int_value(vm)?).into_ref_with_type(vm, cls)
+    }
+
     #[pymethod(name = "__eq__")]
     fn eq(&self, other: PyObjectRef, vm: &VirtualMachine) -> PyObjectRef {
         if objtype::isinstance(&other, &vm.ctx.int_type()) {
@@ -720,10 +725,6 @@ impl IntOptions {
     }
 }
 
-fn int_new(cls: PyClassRef, options: IntOptions, vm: &VirtualMachine) -> PyResult<PyIntRef> {
-    PyInt::new(options.get_int_value(vm)?).into_ref_with_type(vm, cls)
-}
-
 #[derive(FromArgs)]
 struct IntFromByteArgs {
     #[pyarg(positional_or_keyword)]
@@ -935,7 +936,4 @@ fn get_py_int(obj: &PyObjectRef) -> &PyInt {
 
 pub fn init(context: &PyContext) {
     PyInt::extend_class(context, &context.types.int_type);
-    extend_class!(context, &context.types.int_type, {
-        (slot new) => int_new,
-    });
 }
diff --git a/vm/src/obj/objmap.rs b/vm/src/obj/objmap.rs
index 655b561ec..45559ad00 100644
--- a/vm/src/obj/objmap.rs
+++ b/vm/src/obj/objmap.rs
@@ -23,25 +23,26 @@ impl PyValue for PyMap {
     }
 }
 
-fn map_new(
-    cls: PyClassRef,
-    function: PyObjectRef,
-    iterables: Args,
-    vm: &VirtualMachine,
-) -> PyResult<PyMapRef> {
-    let iterators = iterables
-        .into_iter()
-        .map(|iterable| objiter::get_iter(vm, &iterable))
-        .collect::<Result<Vec<_>, _>>()?;
-    PyMap {
-        mapper: function.clone(),
-        iterators,
-    }
-    .into_ref_with_type(vm, cls.clone())
-}
-
 #[pyimpl]
 impl PyMap {
+    #[pyslot(new)]
+    fn tp_new(
+        cls: PyClassRef,
+        function: PyObjectRef,
+        iterables: Args,
+        vm: &VirtualMachine,
+    ) -> PyResult<PyMapRef> {
+        let iterators = iterables
+            .into_iter()
+            .map(|iterable| objiter::get_iter(vm, &iterable))
+            .collect::<Result<Vec<_>, _>>()?;
+        PyMap {
+            mapper: function.clone(),
+            iterators,
+        }
+        .into_ref_with_type(vm, cls.clone())
+    }
+
     #[pymethod(name = "__next__")]
     fn next(&self, vm: &VirtualMachine) -> PyResult {
         let next_objs = self
@@ -62,7 +63,4 @@ impl PyMap {
 
 pub fn init(context: &PyContext) {
     PyMap::extend_class(context, &context.types.map_type);
-    extend_class!(context, &context.types.map_type, {
-        (slot new) => map_new,
-    });
 }