Sveltekit "Files and directories prefixed with __ are reserved" error

I tried using named layout but when running npm run dev --open it gives me this error

> Files and directories prefixed with __ are reserved (saw src/routes/auth/__layout-auth.svelte)
    at file:///home/gwendal/Documents/SvelteKit/ninja-gaming/node_modules/@sveltejs/kit/dist/chunks/sync.js:193:11
    at Array.forEach (<anonymous>)
    at walk (file:///home/gwendal/Documents/SvelteKit/ninja-gaming/node_modules/@sveltejs/kit/dist/chunks/sync.js:178:32)
    at file:///home/gwendal/Documents/SvelteKit/ninja-gaming/node_modules/@sveltejs/kit/dist/chunks/sync.js:235:5
    at Array.forEach (<anonymous>)
    at walk (file:///home/gwendal/Documents/SvelteKit/ninja-gaming/node_modules/@sveltejs/kit/dist/chunks/sync.js:211:9)
    at create_manifest_data (file:///home/gwendal/Documents/SvelteKit/ninja-gaming/node_modules/@sveltejs/kit/dist/chunks/sync.js:296:2)
    at update (file:///home/gwendal/Documents/SvelteKit/ninja-gaming/node_modules/@sveltejs/kit/dist/chunks/sync.js:911:24)
    at update_manifest (file:///home/gwendal/Documents/SvelteKit/ninja-gaming/node_modules/@sveltejs/kit/dist/chunks/index.js:59:31)
    at Object.configureServer (file:///home/gwendal/Documents/SvelteKit/ninja-gaming/node_modules/@sveltejs/kit/dist/chunks/index.js:191:4)

I have a layout called __layout-auth.svelte located in src/routes/auth

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