Serialization of 'Closure' is not allowed in Laravel 5.3 Email Queue
Stefan Bogdanescu
Founder & Senior Architect · 2026-06-29
Title: Understanding and Solving Serialization Issues with Closures in Laravel 5.3 Email Queue
Body:
Serialization issues often arise when working with closures and the Laravel email queue system. In this blog post, we will explore some of these errors and provide solutions to help you avoid them. We'll examine how serialization works in Laravel, why it cannot serialize closures, and various approaches you can take to overcome this challenge.
Understanding Serialization
Serialization is the process of converting a variable or object into a string representation that can be saved later. When objects are serialized, their state and memory content are stored in a binary format that you can restore at a later time. Laravel supports serializing objects by calling serialize() on them. However, it doesn't support serialized closures.Why Closures Cannot Be Serialized
In PHP, a closure is an anonymous function with access to the variables in its surrounding scope. When you try to serialize such a function, the process encounters issues because it relies on external factors that may change during deserialization. These external factors include dependencies on other functions and variables which may not be available or present at the time of deserialization. ☠️Warning: Serializing 'Closure' is not allowed in Laravel 5.3 Email Queue: This error occurs because serializing a closure (anonymous function) isn't possible due to potential issues with accessing external elements and maintaining the state of variables during deserialization.
Possible Solutions
To overcome this obstacle, you can use one of these approaches:- Refactor your code:
- Use a different queue driver:
- Create a custom persistence strategy: