# Use numba dtype with jitclass

**URL:** <https://numba.discourse.group/t/use-numba-dtype-with-jitclass/675>\
**Category:** Support: How do I do ...?\
**Created:** [April 19, 2021, 8:50am UTC](https://numba.discourse.group/t/use-numba-dtype-with-jitclass/675 "2021-04-19T08:50:43Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![joshua](https://avatars.discourse-cdn.com/v4/letter/j/48db29/32.png) [@joshua](https://numba.discourse.group/u/joshua)\
**Post date:** [April 19, 2021, 8:50am UTC](https://numba.discourse.group/t/use-numba-dtype-with-jitclass/675/1 "2021-04-19T08:50:44Z")

</div>

I am having trouble initialising a jitclass with a singular instance of numpy dtype. The following is the code where I am getting the error.  
import numpy as np  
from numba import jitclass, typeof

```
counter_dtype = np.dtype([('element', np.int32, 5)])
one_counter = np.zeros(1, dtype=counter_dtype)[0]

spec = [
    ("counter", typeof(one_counter))
]

@jitclass(spec)
class UpdatingStuff: 
    def __init__ (self, counter):
        self.counter = counter

UpdatingStuff(one_counter)
```

---

<div class="post-metadata">

**Author:** ![stuartarchibald](https://yyz2.discourse-cdn.com/free1/user_avatar/numba.discourse.group/stuartarchibald/32/10_2.png) [@stuartarchibald](https://numba.discourse.group/u/stuartarchibald)\
**Post date:** [April 20, 2021, 3:07pm UTC](https://numba.discourse.group/t/use-numba-dtype-with-jitclass/675/2 "2021-04-20T15:07:58Z")

</div>

Hi @joshua

Just in case anyone else encounters a similar issue, there’s discussion on [https://gitter.im/numba/numba](https://gitter.im/numba/numba) in relation to this here: [numba/numba - Gitter](https://gitter.im/numba/numba?at=607d55082e5574669b46d04c).