Rails 7.1 introduces enum validate option for stricter ActiveRecord enums

Rails 7.1 introduces a subtle but impactful improvement to enum handling with the addition of the validate option.

The Problem Before

Enums have long been used in Rails to map symbolic values to integers — perfect for roles, states, or types. But assigning invalid enum values silently passed validation:

1class Holiday < ApplicationRecord
2  enum kind: [:national, :regional]
3end
4
5holiday = Holiday.new(kind: :optional)
6holiday.valid? # => true

In this case, :optional isn't even defined in the enum, yet no error is raised until it's saved, which causes an ArgumentError. That’s not great DX.

What’s New in Rails 7.1

Rails 7.1 now lets you enforce value-level validations with validate: true:

1class Holiday < ApplicationRecord
2  enum kind: [:national, :regional], validate: true
3end
4
5holiday = Holiday.new(kind: :optional)
6holiday.valid? # => false
7holiday.errors[:kind] # => ["is not a valid kind"]

No more ArgumentErrors. Just clean, predictable validation failures.

Optional Enhancements

You can customize the validation further. For example, to allow nil as a valid value:

1class Holiday < ApplicationRecord
2  enum kind: [:national, :regional], validate: { allow_nil: true }
3end

Now holiday.kind = nil passes, but invalid values still fail validation.

Why It Matters

This change brings enums in line with the rest of Rails' validation philosophy — fail fast and fail clearly.

It’s especially helpful for apps accepting enum values via API params or forms, where invalid data might sneak in.

References

• PR #49100 – Adds validate option for enums
• Rails 7.1 Release Notes

Summary

Enums are safer now. With validate: true, Rails 7.1 lets your models reject invalid values before they hit the database — no surprises, just clean validations.