# Xcode 12.4 - macOS Big Sur - compiling for iOS \< 13 - CryptoKit error

**URL:** <https://forums.fusetools.com/t/xcode-12-4-macos-big-sur-compiling-for-ios-13-cryptokit-error/8115>\
**Category:** How-to Discussions\
**Created:** [March 17, 2021, 7:12pm UTC](https://forums.fusetools.com/t/xcode-12-4-macos-big-sur-compiling-for-ios-13-cryptokit-error/8115 "2021-03-17T19:12:32Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![aeq](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/aeq/32/129_2.png) [@aeq](https://forums.fusetools.com/u/aeq)\
**Post date:** [March 17, 2021, 7:12pm UTC](https://forums.fusetools.com/t/xcode-12-4-macos-big-sur-compiling-for-ios-13-cryptokit-error/8115/1 "2021-03-17T19:12:33Z")

</div>

If you’re getting the following error on app launch when trying to include iOS 12 devices for instance:

```auto
dyld: Library not loaded: /System/Library/Frameworks/CryptoKit.framework/CryptoKit

```

Xcode is not properly adding `CryptoKit` to the linked frameworks list. To solve this issue, you must manually add the `-weak_framework CryptoKit` flag in your app’s target.

 ![Screenshot 2021-03-17 at 21.10.40](https://canada1.discourse-cdn.com/flex035/uploads/fusetools1/original/2X/5/507729f578cd9703918eca062126b333fddbf736.png)

Ref: [Conditionally use CryptoKit - #13 by bjhomer - Using Swift - Swift Forums](https://forums.swift.org/t/conditionally-use-cryptokit/30138/13)