# Excluding Dev Dependencies also deleting necessary modules

**URL:** <https://forum.serverless.com/t/excluding-dev-dependencies-also-deleting-necessary-modules/10252>\
**Category:** Serverless Framework\
**Tags:** lambda\
**Created:** [January 14, 2020, 3:12pm UTC](https://forum.serverless.com/t/excluding-dev-dependencies-also-deleting-necessary-modules/10252 "2020-01-14T15:12:33Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![bertero](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.serverless.com/bertero/32/3882_2.png) [@bertero](https://forum.serverless.com/u/bertero)\
**Post date:** [January 14, 2020, 3:12pm UTC](https://forum.serverless.com/t/excluding-dev-dependencies-also-deleting-necessary-modules/10252/1 "2020-01-14T15:12:33Z")

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Hello guys, please help me out here. This is an issue happening for us for a while now.

When we choose to `excludeDevDependencies: true`, there are also some necessary modules being deleted from the deployed package. What happens is that our lambda function, after deployment, keeps logging the message  
`"ERROR Uncaught Exception {"errorType":"Runtime.ImportModuleError","errorMessage":"Error: Cannot find module <some-module>"} "`

We tried to simply skip the excluding step by `excludeDevDependencies: false`. However this generates a package too large to be deployed in a lambda function.

Does anyone have an idea here?

FYI: we use yarn instead of npm. Don’t know if it changes anything, I believe it shouldn’t.

Thanks in advance!

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**Author:** ![FilipPyrek](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.serverless.com/filippyrek/32/3920_2.png) [@FilipPyrek](https://forum.serverless.com/u/FilipPyrek)\
**Post date:** [January 23, 2020, 11:56pm UTC](https://forum.serverless.com/t/excluding-dev-dependencies-also-deleting-necessary-modules/10252/2 "2020-01-23T23:56:20Z")

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Hi, so move the necessary module from `"devDependencies"` to `"dependencies"` in `package.json`. I think that that could solve it.

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**Author:** ![jfn0](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.serverless.com/jfn0/32/3900_2.png) [@jfn0](https://forum.serverless.com/u/jfn0)\
**Post date:** [January 24, 2020, 4:56am UTC](https://forum.serverless.com/t/excluding-dev-dependencies-also-deleting-necessary-modules/10252/3 "2020-01-24T04:56:03Z")

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You should take a look at this plugin

> **[serverless-plugin-browserify](https://www.npmjs.com/package/serverless-plugin-browserify)**
>
> Serverless v1.0 plugin that uses Browserify to bundle NodeJS Lambda functions.

It will bundle you lambda in a single file with only the required xeps. Smaller size and faster coldstart…