Ruby on Rails v8.1.3 released!

NewsBot · 24 March 2026 22:25

Ruby on Rails v8.1.3 has been released.

Active Support
Fix JSONGemCoderEncoder to correctly serialize custom object hash keys.

When hash keys are custom objects whose as_json returns a Hash,
the encoder now calls to_s on the original key object instead of
on the as_json result.

Before:
hash = {CustomKey.new(123) => “value”}
hash.to_json # => {“{:id=>123}”:“value”}

After:
hash.to_json # => {“custom_123”:“value”}

Dan Sharp
Fix inflections to better handle overlapping acronyms.
ActiveSupport::Inflector.inflections(:en) do |inflect|
  inflect.acronym "USD"
  inflect.acronym "USDC"
end

"USDC".underscore # => "usdc"
Said Kaldybaev
Silence Dalli 4.0+ warning when using ActiveSupport::Cache::MemCacheStore.

zzak
Active Model

Fix Ruby 4.0 delegator warning when calling inspect on attributes.

Hammad Khan

Fix NoMethodError when deserialising Type::Integer objects marshalled under Rails 8.0.

The performance optimisation that replaced @range with @max/@min
broke Marshal compatibility. Objects serialised under 8.0 (with @range)
and deserialised under 8.1 (expecting @max/@min) would crash with
undefined method '<=' for nil because Marshal.load restores instance
variables without calling initialize.

Edward Woodcock

Active Record

Fix insert_all and upsert_all log message when called on anonymous classes.

Gabriel Sobrinho

Respect ActiveRecord::SchemaDumper.ignore_tables when dumping SQLite virtual tables.

Hans Schnedlitz

Restore previous instrumenter after execute_or_skip

FutureResult#execute_or_skip replaces the thread’s instrumenter with an
EventBuffer to collect events published during async query execution.
If the global async executor is saturated and the caller_runs fallback
ex…

Link: Release 8.1.3 · rails/rails · GitHub