diff --git a/vm/src/obj/objslice.rs b/vm/src/obj/objslice.rs
index 9df435290..d68ae2255 100644
--- a/vm/src/obj/objslice.rs
+++ b/vm/src/obj/objslice.rs
@@ -1,9 +1,7 @@
 use num_bigint::BigInt;
 
 use crate::function::PyFuncArgs;
-use crate::pyobject::{
-    FromPyObjectRef, PyContext, PyObject, PyObjectRef, PyResult, PyValue, TypeProtocol,
-};
+use crate::pyobject::{PyContext, PyObjectRef, PyResult, PyValue, TypeProtocol};
 use crate::vm::VirtualMachine;
 
 use super::objint;
@@ -57,14 +55,13 @@ fn slice_new(vm: &VirtualMachine, args: PyFuncArgs) -> PyResult {
             Ok((cls, Some(start), Some(stop), step))
         }
     }?;
-    Ok(PyObject::new(
-        PySlice {
-            start: start.map(|x| objint::get_value(x).clone()),
-            stop: stop.map(|x| objint::get_value(x).clone()),
-            step: step.map(|x| objint::get_value(x).clone()),
-        },
-        PyClassRef::from_pyobj(&cls),
-    ))
+    PySlice {
+        start: start.map(|x| objint::get_value(x).clone()),
+        stop: stop.map(|x| objint::get_value(x).clone()),
+        step: step.map(|x| objint::get_value(x).clone()),
+    }
+    .into_ref_with_type(vm, cls.clone().downcast().unwrap())
+    .map(|x| x.into_object())
 }
 
 fn get_property_value(vm: &VirtualMachine, value: &Option<BigInt>) -> PyResult {
diff --git a/vm/src/obj/objtype.rs b/vm/src/obj/objtype.rs
index 1b53226c9..b48ba9941 100644
--- a/vm/src/obj/objtype.rs
+++ b/vm/src/obj/objtype.rs
@@ -241,7 +241,7 @@ pub fn type_new_class(
     bases.push(vm.ctx.object());
     let name = objstr::get_value(name);
     new(
-        PyClassRef::from_pyobj(typ),
+        typ.clone().downcast().unwrap(),
         &name,
         bases,
         objdict::py_dict_to_attributes(dict),
@@ -382,7 +382,7 @@ pub fn new(
         typ,
     }
     .into_ref();
-    Ok(PyClassRef::from_pyobj(&new_type))
+    Ok(new_type.downcast().unwrap())
 }
 
 #[cfg(test)]
diff --git a/vm/src/pyobject.rs b/vm/src/pyobject.rs
index deeb4f370..80eba36da 100644
--- a/vm/src/pyobject.rs
+++ b/vm/src/pyobject.rs
@@ -206,8 +206,8 @@ fn init_type_hierarchy() -> (PyClassRef, PyClassRef) {
         let object_type_ptr = PyObjectRef::into_raw(object_type.clone()) as *mut PyObject<PyClass>;
         let type_type_ptr = PyObjectRef::into_raw(type_type.clone()) as *mut PyObject<PyClass>;
 
-        let type_type = PyClassRef::from_pyobj(&type_type);
-        let object_type = PyClassRef::from_pyobj(&object_type);
+        let type_type: PyClassRef = type_type.downcast().unwrap();
+        let object_type: PyClassRef = object_type.downcast().unwrap();
 
         ptr::write(&mut (*object_type_ptr).typ, type_type.clone());
         ptr::write(&mut (*type_type_ptr).typ, type_type.clone());