# How to import library into library on forc v0.37.0?

**URL:** <https://forum.fuel.network/t/how-to-import-library-into-library-on-forc-v0-37-0/2276>\
**Category:** Sway\
**Created:** [April 7, 2023, 3:46pm UTC](https://forum.fuel.network/t/how-to-import-library-into-library-on-forc-v0-37-0/2276 "2023-04-07T15:46:23Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![fuel](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.fuel.network/fuel/32/1677_2.png) [@fuel](https://forum.fuel.network/u/fuel)\
**Post date:** [April 7, 2023, 3:46pm UTC](https://forum.fuel.network/t/how-to-import-library-into-library-on-forc-v0-37-0/2276/1 "2023-04-07T15:46:23Z")

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Hi guys  
We noticed library declarations were updated on forc v0.37.0 and I have a question  
`src` folder contains 3 files: a contract `main.sw` and 2 libraries: `structs.sw` and `i64.sw`.  
We need to use `i64.sw` inside `main.sw` and inside `structs.sw`

### `main.sw`

```auto
contract;

mod structs;
mod i64;

use i64::I64;
use structs::*;

...

```

### `i64.sw`

```auto
library;
...

```

### `structs.sw`

```auto
library;

mod i64;
use i64::I64;

```

But when I’m trying to compile I have an error

 ![image](https://us1.discourse-cdn.com/flex022/uploads/fuel/original/2X/d/d978983242155cf4a06460c8df6228b1d0fe2d4a.png)

Please help manage the libraries

---

<div class="post-metadata">

**Author:** ![sarah](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.fuel.network/sarah/32/13_2.png) [@sarah](https://forum.fuel.network/u/sarah)\
**Post date:** [April 10, 2023, 4:34pm UTC](https://forum.fuel.network/t/how-to-import-library-into-library-on-forc-v0-37-0/2276/2 "2023-04-10T16:34:31Z")

</div>

I believe you have to move the i64 to an external library in order to use it like this. You can find the instructions for how to set this up in the Sway book here: [Libraries - The Sway Programming Language](https://fuellabs.github.io/sway/master/book/sway-program-types/libraries.html#external-libraries)