diff --git a/vm/src/builtins/memory.rs b/vm/src/builtins/memory.rs
index a34d8db3a..8b1777356 100644
--- a/vm/src/builtins/memory.rs
+++ b/vm/src/builtins/memory.rs
@@ -1,6 +1,5 @@
 use super::{
-    PyBytes, PyBytesRef, PyInt, PyList, PyListRef, PySlice, PyStr, PyStrRef, PyTuple, PyTupleRef,
-    PyTypeRef,
+    PyBytes, PyBytesRef, PyInt, PyListRef, PySlice, PyStr, PyStrRef, PyTuple, PyTupleRef, PyTypeRef,
 };
 use crate::common::{
     borrow::{BorrowedValue, BorrowedValueMut},
@@ -630,15 +629,13 @@ impl PyMemoryView {
                 ));
             }
 
-            let tup = shape.payload_if_subclass::<PyTuple>(vm);
-            let list = shape.payload_if_subclass::<PyList>(vm);
-
-            let l = tup.map(|t| PyList::from(t.as_slice().iter().cloned().collect_vec()));
-            let list_from_tuple = l.as_ref();
-
-            let shape = list.xor(list_from_tuple).ok_or_else(|| {
-                vm.new_type_error("memoryview: must be a list or a tuple".to_owned())
-            })?;
+            let shape = match shape {
+                Either::A(tup) => {
+                    let elements = tup.as_slice().iter().cloned().collect_vec();
+                    vm.ctx.new_list(elements)
+                }
+                Either::B(list) => list,
+            };
 
             let shape_vec = shape.borrow_vec();
             let shape_ndim = shape_vec.len();