# Error returning expval with qiskit device

**URL:** <https://discuss.pennylane.ai/t/error-returning-expval-with-qiskit-device/2473>\
**Category:** PennyLane Help\
**Created:** [January 30, 2023, 9:00am UTC](https://discuss.pennylane.ai/t/error-returning-expval-with-qiskit-device/2473 "2023-01-30T09:00:29Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![psansebastian](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/psansebastian/32/2049_2.png) [@psansebastian](https://discuss.pennylane.ai/u/psansebastian)\
**Post date:** [January 30, 2023, 9:00am UTC](https://discuss.pennylane.ai/t/error-returning-expval-with-qiskit-device/2473/1 "2023-01-30T09:00:29Z")

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Hi!  
I’m trying to use qiskit’s Aer simulator in my Pennyalne program but I get an error when te circuit tries to return an expected value:

‘RY’ object has no attribute ‘return\_type’

Here is a simple example:

```auto
def circuit1():
    qml.RY(np.pi/4, wires=0)
    return qml.expval(qml.PauliZ(wires=0))

dev1 = qml.device("qiskit.aer", wires=1)
node = qml.QNode(circuit1, dev1)

fig,ax=qml.draw_mpl(node,expansion_strategy="device", decimals=1)()

print(node())

```

![descarga](https://canada1.discourse-cdn.com/flex012/uploads/pennylane/original/2X/d/de90577becffe5d1275e6175a689f3557e745ead.png)

Thank you in advance!

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<div class="post-metadata">

**Author:** ![CatalinaAlbornoz](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/catalinaalbornoz/32/1196_2.png) [@CatalinaAlbornoz](https://discuss.pennylane.ai/u/CatalinaAlbornoz)\
**Post date:** [January 31, 2023, 11:04pm UTC](https://discuss.pennylane.ai/t/error-returning-expval-with-qiskit-device/2473/2 "2023-01-31T23:04:15Z")

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Hi @psansebastian, welcome to the Forum!

I’m running your circuit on a notebook [Xanadu Cloud](https://cloud.xanadu.ai) and I get no errors. Could you please post the output of `qml.about()`? I’m guessing that you might be using an old version of PennyLane. You can use `python -m pip install pennylane --upgrade` to make sure you’re using the latest version.

Please let me know if this solves your issue!

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**Author:** ![psansebastian](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/psansebastian/32/2049_2.png) [@psansebastian](https://discuss.pennylane.ai/u/psansebastian)\
**Post date:** [February 1, 2023, 8:12am UTC](https://discuss.pennylane.ai/t/error-returning-expval-with-qiskit-device/2473/3 "2023-02-01T08:12:37Z")

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> [@CatalinaAlbornoz](#):
>
> pip install pennylane --upgrade

Thank you for replying! Seems that updating Pennylane fixed it!

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**Author:** ![CatalinaAlbornoz](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/catalinaalbornoz/32/1196_2.png) [@CatalinaAlbornoz](https://discuss.pennylane.ai/u/CatalinaAlbornoz)\
**Post date:** [February 6, 2023, 3:39pm UTC](https://discuss.pennylane.ai/t/error-returning-expval-with-qiskit-device/2473/4 "2023-02-06T15:39:38Z")

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I’m glad this solved your issue @psansebastian!

Enjoy using PennyLane 😀