Laravel Undefined Constant header_x_forwarded_all after upgrading Laravel version

By Dillon Smart · · · 5 Comments

Laravel undefined constant error

Upgrading to a newer version of Laravel can be exciting, but it can also be nerve racking if you are unfamiliar with the changes in newer version, especially if your upgrading multiple times. Have you received an “Undefined Constant” error in Laravel after upgrading?

In this post, I will help you understand the changes under the hood in Laravel and it’s dependencies. We will learn how to fix the error “Undefined Constant llluminate\Http\Request::HEADER_X_FORWARDED_ALL” caused when running composer update.

Undefined Constant llluminate\Http\Request::HEADER_X_FORWARDED_ALL

The error is caused by Laravel dropping the Fideloper/proxy package from Laravel 9, and it can be easy to miss on the official documentation. As of Laravel 9, Fideloper/proxy has been incorporated into the core of Laravel.

You can find more information on this here.

The Laravel team states the likelihood of impact for this error is low, and thankfully it’s a quick and easy fix. 

What’s changed in Laravel?

The cause of the Undefined Constant llluminate\Http\Request::HEADER_X_FORWARDED_ALL error in Laravel

The cause of the HEADER_X_FORWARDED_ALL error comes from the Symfony HttpFoundation component used by Laravel. Laravel previously used HEADER_X_FORWARDED_ALL constant for the value of the $headers property in the TrustProxies.php file, however since Symfony 5.2 this was deprecated, and finally removed in version 6.0.

When upgrading to Laravel 9, composer upgrades dependencies as well. When the Symfony HttpFoundation package is upgraded, the Undefined Constant llluminate\Http\Request::HEADER_X_FORWARDED_ALL error is thrown.

The solution to fix the Laravel Undefined Constant error

Follow the steps below to fix the Undefined constant Illuminate\Http\Request::HEADER_X_FORWARDED_ALLerror.

Within your app open /Http/Middleware/TrustProxies.php  and update line 5.

Use Fideloper\Proxy\TrustProxies as Middle;

Change this line to: 

Use Illuminate\Http\Middleware\TrustProxies as Middleware;

Next, you need to update the $headers property. 

Laravel Middleware Request Headers
protected $headers =






And finally, you can remove fideloper/proxy composer dependency from your application: 

composer remove fideloper/proxy

Learn more about Composer

You can read more about the changes required when upgrading to Laravel in the official upgrade guide under the Trusted Proxies subheading.


I hope this has helped you fix the Undefined Constant llluminate\Http\Request::HEADER_X_FORWARDED_ALLerror when upgrading to Laravel

If you are having any trouble please leave a comment below and I will try to help you solve the Undefined Constant llluminate\Http\Request::HEADER_X_FORWARDED_ALLerror.



Tiago Farias



thank you it helped me


Thank you!!

Mohammed Rahat Hossain

Thanks this post helps me a lot

Erick Jeronimo

Thanks a lot!

Was this helpful? Leave a comment!

This site uses Akismet to reduce spam. Learn how your comment data is processed.

How to use Microsoft Graph API with Laravel

Updated 1st January 2024

Microsoft Graph is a gateway to data and intelligence within Microsoft 365. Microsoft Graph is great to build apps for organizations and consumers using the vast amount of data stored in Microsoft 365. In this post, we are going to integrate with Microsoft Graph API in Laravel to get all users assigned to your tenant.

Laravel – Specified key was too long Error

Updated 18th May 2021

With Laravel 5.4, some users may be hit with the Laravel Specified key was too long Error when migrating the database. This is because in the latest Laravel update, the developers made changes to the default database charset, making it utf8mb4. If your using MySQL 5.7.7 or higher, you won’t encounter this issue, however older versions of MySQL

2022 PHP Usage Statistics

Updated 16th August 2022

PHP: Hypertext Preprocessor is the most popular language used on the web. Around 77.6% of all websites run PHP in some way as of April 2022. PHP has been the driving force behind the growth of the web, but is it slowly dying? Let’s look at some PHP usage statistics. Why is PHP so popular?