diff --git a/Lib/test/test_deque.py b/Lib/test/test_deque.py
index f798ab4b6..d4b42c0bd 100644
--- a/Lib/test/test_deque.py
+++ b/Lib/test/test_deque.py
@@ -817,7 +817,6 @@ class TestSubclass(unittest.TestCase):
         d.clear()
         self.assertEqual(len(d), 0)
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; AttributeError: 'Deque' object has no attribute 'x'
     def test_copy_pickle(self):
         for cls in Deque, DequeWithSlots:
             for d in cls('abc'), cls('abcde', maxlen=4):
diff --git a/crates/vm/src/stdlib/_collections.rs b/crates/vm/src/stdlib/_collections.rs
index 2807e1717..8eacc69f0 100644
--- a/crates/vm/src/stdlib/_collections.rs
+++ b/crates/vm/src/stdlib/_collections.rs
@@ -388,7 +388,11 @@ mod _collections {
                 Some(v) => vm.new_pyobj((vm.ctx.empty_tuple.clone(), v)),
                 None => vm.ctx.empty_tuple.clone().into(),
             };
-            Ok(vm.new_pyobj((cls, value, vm.ctx.none(), PyDequeIterator::new(zelf))))
+            // Use __getstate__ to capture both __dict__ and __slots__ values so
+            // subclass attributes survive a pickle round-trip (matches CPython's
+            // deque___reduce___impl, which calls _PyObject_GetState).
+            let state = vm.call_method(zelf.as_object(), "__getstate__", ())?;
+            Ok(vm.new_pyobj((cls, value, state, PyDequeIterator::new(zelf))))
         }
 
         #[pyclassmethod]