diff --git a/Appraisals b/Appraisals
index a50ddc6..85db27e 100644
--- a/Appraisals
+++ b/Appraisals
@@ -1,25 +1,15 @@
-appraise "rails-6" do
-  gem "activerecord", "~> 6.1.4"
-  gem "activesupport", "~> 6.1.4"
-  gem "mutex_m", "~> 0.3.0"
-  gem "base64"
+appraise "rails-7.1" do
+  gem "activerecord", "~> 7.1.0"
+  gem "activesupport", "~> 7.1.0"
   gem "bigdecimal"
-  gem "sqlite3", "~> 1.4"
-
-  # Fixes uninitialized constant ActiveSupport::LoggerThreadSafeLevel::Logger (NameError)
-  gem "concurrent-ruby", "< 1.3.5"
+  gem "sqlite3", "~> 2.6.0"
 end
 
-appraise "rails-7" do
-  gem "activerecord", "~> 7.0.1"
-  gem "activesupport", "~> 7.0.1"
-  gem "mutex_m", "~> 0.3.0"
-  gem "base64"
+appraise "rails-7.2" do
+  gem "activerecord", "~> 7.2.0"
+  gem "activesupport", "~> 7.2.0"
   gem "bigdecimal"
-  gem "sqlite3", "~> 1.4"
-
-  # Fixes uninitialized constant ActiveSupport::LoggerThreadSafeLevel::Logger (NameError)
-  gem "concurrent-ruby", "< 1.3.5"
+  gem "sqlite3", "~> 2.6.0"
 end
 
 appraise "rails-8" do
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 004a5ca..5d0af39 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,13 @@
+# 2.0
+* **BREAKING CHANGE:** Minimum Rails version is now 7.1 (dropped Rails 6.x and 7.0)
+* **BREAKING CHANGE:** Minimum Ruby version is now 3.2
+* Added support for Rails 7.1 and 7.2 in test matrix
+* Reimplemented internals on top of Rails 7.1's `ActiveRecord::Base.normalizes`. The `sanitizes` DSL is unchanged, but normalization now runs at **attribute assignment time** instead of `before_save`. This produces a few subtle behavior changes:
+  * **Read-after-write returns the normalized value.** `person.name = " john "; person.name` now returns `"john"` immediately, not `" john "`. Validations and any pre-save reads see normalized values.
+  * **Legacy un-normalized rows are no longer rewritten on every save.** Previously the `before_save` callback rewrote every declared column on each save, opportunistically cleaning up old data. To migrate legacy rows now, reassign the attribute or call `record.normalize_attribute(:col)` before saving.
+  * **`where` and `find_by` hash conditions now normalize their input.** `User.where(email: " X@Y.com ")` will match a row stored as `"x@y.com"`. Raw-SQL conditions (`where("email = ?", ...)`) still bypass normalization.
+  * Apps upgrading from Rails < 7.1 should set `config.active_record.marshalling_format_version = 7.1` to avoid `TypeError` when marshalling records with normalized attributes.
+
 # 1.2
 * Official support for Rails 8
 * Official support for Ruby 3.4
diff --git a/CLAUDE.md b/CLAUDE.md
new file mode 100644
index 0000000..11afdcb
--- /dev/null
+++ b/CLAUDE.md
@@ -0,0 +1,50 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## What This Is
+
+The `sanitization` gem is a Ruby gem that adds automatic string sanitization to ActiveRecord models via a `before_save` callback. It can strip whitespace, collapse multiple spaces, convert empty strings to nil, and apply case transformations.
+
+## Commands
+
+```bash
+# Run tests (default rake task)
+rake spec
+
+# Run tests with RSpec directly
+bundle exec rspec
+
+# Run a single test file or example
+bundle exec rspec spec/sanitization_spec.rb
+bundle exec rspec spec/sanitization_spec.rb:42
+
+# Run tests across all supported Rails versions (6, 7, 8)
+bundle exec appraisal rspec
+
+# Run tests for a specific Rails version
+bundle exec appraisal rails-8 rspec
+
+# Install appraisal gemfiles after changing Appraisals file
+bundle exec appraisal install
+```
+
+## Architecture
+
+The gem has three core files:
+
+- **`lib/sanitization/configuration.rb`** - `Sanitization::Configuration` class with global defaults (strip, collapse, case, nullify, include_text_type). `simple_defaults!` is a shortcut that enables strip + collapse + nullify.
+- **`lib/sanitization/active_record_extension.rb`** - The core logic. `ClassMethods.sanitizes()` introspects table columns, filters by type (string, optionally text), validates options, and stores per-column config in `@sanitization__store`. Registers a `before_save` callback that applies transformations in order: strip -> collapse -> nullify -> case.
+- **`lib/sanitization.rb`** - Entry point that includes `ActiveRecordExtension` into `ActiveRecord::Base` via `class_eval`.
+
+## Testing
+
+Tests use RSpec with an in-memory SQLite database. The `spec_helper.rb` creates a `people` table with string, text, date, and integer columns. A custom `String#leetcase` method is defined for testing custom case transformations.
+
+CI runs on Ruby 3.2, 3.3, 3.4 against Rails 6.1, 7.0, and 8.0 via Appraisal.
+
+Note: ActiveSupport 7+ changed `titlecase` behavior (it strips leading spaces), which affects test expectations between Rails versions.
+
+## Changelog Workflow
+
+Track changes in the `## Unreleased` section of `CHANGELOG.md` as they are made. When a new version is released, rename the `## Unreleased` heading to the version number (e.g., `# 1.3`) and add a fresh `## Unreleased` section above it.
diff --git a/Gemfile.lock b/Gemfile.lock
index 9b38135..4d5795c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,9 +1,9 @@
 PATH
   remote: .
   specs:
-    sanitization (1.2.0)
-      activerecord
-      activesupport
+    sanitization (2.0.0)
+      activerecord (>= 7.1)
+      activesupport (>= 7.1)
 
 GEM
   remote: https://rubygems.org/
@@ -43,7 +43,10 @@ GEM
     i18n (1.14.7)
       concurrent-ruby (~> 1.0)
     logger (1.7.0)
-    minitest (5.25.5)
+    minitest (6.0.5)
+      drb (~> 2.0)
+      prism (~> 1.5)
+    prism (1.9.0)
     rake (13.2.1)
     rspec (3.13.0)
       rspec-core (~> 3.13.0)
@@ -59,16 +62,16 @@ GEM
       rspec-support (~> 3.13.0)
     rspec-support (3.13.2)
     securerandom (0.4.1)
-    sqlite3 (2.6.0-aarch64-linux-gnu)
-    sqlite3 (2.6.0-aarch64-linux-musl)
-    sqlite3 (2.6.0-arm-linux-gnu)
-    sqlite3 (2.6.0-arm-linux-musl)
-    sqlite3 (2.6.0-arm64-darwin)
-    sqlite3 (2.6.0-x86-linux-gnu)
-    sqlite3 (2.6.0-x86-linux-musl)
-    sqlite3 (2.6.0-x86_64-darwin)
-    sqlite3 (2.6.0-x86_64-linux-gnu)
-    sqlite3 (2.6.0-x86_64-linux-musl)
+    sqlite3 (2.9.3-aarch64-linux-gnu)
+    sqlite3 (2.9.3-aarch64-linux-musl)
+    sqlite3 (2.9.3-arm-linux-gnu)
+    sqlite3 (2.9.3-arm-linux-musl)
+    sqlite3 (2.9.3-arm64-darwin)
+    sqlite3 (2.9.3-x86-linux-gnu)
+    sqlite3 (2.9.3-x86-linux-musl)
+    sqlite3 (2.9.3-x86_64-darwin)
+    sqlite3 (2.9.3-x86_64-linux-gnu)
+    sqlite3 (2.9.3-x86_64-linux-musl)
     thor (1.3.2)
     timeout (0.4.3)
     tzinfo (2.0.6)
@@ -91,7 +94,6 @@ PLATFORMS
 DEPENDENCIES
   appraisal (~> 2.5)
   byebug
-  concurrent-ruby (< 1.3.5)
   cucumber-ci-environment
   rake (~> 13.2)
   rspec (~> 3.0)
diff --git a/README.md b/README.md
index fc363b0..3718d82 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,19 @@ Sanitization makes it easy to store slightly cleaner strings to your database.
 - Change casing (ie. upcase, downcase, titlecase, etc)
 
 
+### Built on top of `ActiveRecord::Base.normalizes`
+
+As of 2.0, Sanitization is a thin macro layer on top of Rails 7.1's [`ActiveRecord::Base.normalizes`](https://api.rubyonrails.org/classes/ActiveRecord/Normalization/ClassMethods.html). The `sanitizes` DSL is unchanged — under the hood, each declared column is registered with `normalizes`, and Sanitization composes a single normalizer per column from your `:strip`, `:collapse`, `:nullify`, and `:case` options (plus their global defaults).
+
+Because `normalizes` runs at attribute **assignment** time (not `before_save`), this gives you a few useful behaviors automatically:
+
+- **Read-after-write returns the normalized value.** `person.name = " john "; person.name` returns `"john"` immediately — validations and any pre-save reads see the cleaned value.
+- **`where`/`find_by` hash conditions normalize the lookup value.** `User.where(email: "  RAW@X.COM  ")` matches a row stored as `"raw@x.com"`. (Raw-SQL conditions still bypass normalization.)
+- **Legacy un-normalized rows are not silently rewritten on save.** Reload + save no longer "heals" old data. To migrate, reassign the attribute or call `record.normalize_attribute(:col)` (a built-in helper from `normalizes`).
+
+If you're upgrading from 1.x, see the CHANGELOG for the full list of behavior changes.
+
+
 ### Defaults
 
 By default, Sanitization has all options disabled. It is recommended you use a configuration block to set
@@ -45,6 +58,11 @@ Sanitization.simple_defaults!
 - Change casing: (`case: :none|:up|:down|:custom`)
 
 
+## Compatibility
+
+- Ruby >= 3.2
+- Rails >= 7.1
+
 ## Installation
 
 ```sh
diff --git a/gemfiles/rails_6.gemfile.lock b/gemfiles/rails_6.gemfile.lock
deleted file mode 100644
index 344e545..0000000
--- a/gemfiles/rails_6.gemfile.lock
+++ /dev/null
@@ -1,86 +0,0 @@
-PATH
-  remote: ..
-  specs:
-    sanitization (1.1.4)
-      activerecord
-      activesupport
-
-GEM
-  remote: https://rubygems.org/
-  specs:
-    activemodel (6.1.7.10)
-      activesupport (= 6.1.7.10)
-    activerecord (6.1.7.10)
-      activemodel (= 6.1.7.10)
-      activesupport (= 6.1.7.10)
-    activesupport (6.1.7.10)
-      concurrent-ruby (~> 1.0, >= 1.0.2)
-      i18n (>= 1.6, < 2)
-      minitest (>= 5.1)
-      tzinfo (~> 2.0)
-      zeitwerk (~> 2.3)
-    appraisal (2.5.0)
-      bundler
-      rake
-      thor (>= 0.14.0)
-    base64 (0.2.0)
-    bigdecimal (3.1.9)
-    byebug (12.0.0)
-    concurrent-ruby (1.3.4)
-    cucumber-ci-environment (10.0.1)
-    diff-lcs (1.6.1)
-    i18n (1.14.7)
-      concurrent-ruby (~> 1.0)
-    mini_portile2 (2.8.8)
-    minitest (5.25.5)
-    mutex_m (0.3.0)
-    rake (13.2.1)
-    rspec (3.13.0)
-      rspec-core (~> 3.13.0)
-      rspec-expectations (~> 3.13.0)
-      rspec-mocks (~> 3.13.0)
-    rspec-core (3.13.3)
-      rspec-support (~> 3.13.0)
-    rspec-expectations (3.13.3)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.13.0)
-    rspec-mocks (3.13.2)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.13.0)
-    rspec-support (3.13.2)
-    sqlite3 (1.7.3)
-      mini_portile2 (~> 2.8.0)
-    thor (1.3.2)
-    tzinfo (2.0.6)
-      concurrent-ruby (~> 1.0)
-    zeitwerk (2.7.2)
-
-PLATFORMS
-  aarch64-linux-gnu
-  aarch64-linux-musl
-  arm-linux-gnu
-  arm-linux-musl
-  arm64-darwin
-  x86-linux-gnu
-  x86-linux-musl
-  x86_64-darwin
-  x86_64-linux-gnu
-  x86_64-linux-musl
-
-DEPENDENCIES
-  activerecord (~> 6.1.4)
-  activesupport (~> 6.1.4)
-  appraisal (~> 2.5)
-  base64
-  bigdecimal
-  byebug
-  concurrent-ruby (< 1.3.5)
-  cucumber-ci-environment
-  mutex_m (~> 0.3.0)
-  rake (~> 13.2)
-  rspec (~> 3.0)
-  sanitization!
-  sqlite3 (~> 1.4)
-
-BUNDLED WITH
-   2.6.3
diff --git a/gemfiles/rails_6.gemfile b/gemfiles/rails_7.1.gemfile
similarity index 58%
rename from gemfiles/rails_6.gemfile
rename to gemfiles/rails_7.1.gemfile
index 5084a08..3291eb6 100644
--- a/gemfiles/rails_6.gemfile
+++ b/gemfiles/rails_7.1.gemfile
@@ -6,13 +6,10 @@ gem "rake", "~> 13.2"
 gem "rspec", "~> 3.0"
 gem "appraisal", "~> 2.5"
 gem "cucumber-ci-environment"
-gem "sqlite3", "~> 1.4"
+gem "sqlite3", "~> 2.6.0"
 gem "byebug"
-gem "activerecord", "~> 6.1.4"
-gem "activesupport", "~> 6.1.4"
-gem "mutex_m", "~> 0.3.0"
-gem "base64"
+gem "activerecord", "~> 7.1.0"
+gem "activesupport", "~> 7.1.0"
 gem "bigdecimal"
-gem "concurrent-ruby", "< 1.3.5"
 
 gemspec path: "../"
diff --git a/gemfiles/rails_7.1.gemfile.lock b/gemfiles/rails_7.1.gemfile.lock
new file mode 100644
index 0000000..4caea02
--- /dev/null
+++ b/gemfiles/rails_7.1.gemfile.lock
@@ -0,0 +1,113 @@
+PATH
+  remote: ..
+  specs:
+    sanitization (2.0.0)
+      activerecord (>= 7.1)
+      activesupport (>= 7.1)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    activemodel (7.1.6)
+      activesupport (= 7.1.6)
+    activerecord (7.1.6)
+      activemodel (= 7.1.6)
+      activesupport (= 7.1.6)
+      timeout (>= 0.4.0)
+    activesupport (7.1.6)
+      base64
+      benchmark (>= 0.3)
+      bigdecimal
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      connection_pool (>= 2.2.5)
+      drb
+      i18n (>= 1.6, < 2)
+      logger (>= 1.4.2)
+      minitest (>= 5.1)
+      mutex_m
+      securerandom (>= 0.3)
+      tzinfo (~> 2.0)
+    appraisal (2.5.0)
+      bundler
+      rake
+      thor (>= 0.14.0)
+    base64 (0.3.0)
+    benchmark (0.5.0)
+    bigdecimal (4.1.2)
+    byebug (13.0.0)
+      reline (>= 0.6.0)
+    concurrent-ruby (1.3.6)
+    connection_pool (3.0.2)
+    cucumber-ci-environment (13.0.0)
+    diff-lcs (1.6.2)
+    drb (2.2.3)
+    i18n (1.14.8)
+      concurrent-ruby (~> 1.0)
+    io-console (0.8.2)
+    logger (1.7.0)
+    mini_portile2 (2.8.9)
+    minitest (6.0.5)
+      drb (~> 2.0)
+      prism (~> 1.5)
+    mutex_m (0.3.0)
+    prism (1.9.0)
+    rake (13.4.2)
+    reline (0.6.3)
+      io-console (~> 0.5)
+    rspec (3.13.2)
+      rspec-core (~> 3.13.0)
+      rspec-expectations (~> 3.13.0)
+      rspec-mocks (~> 3.13.0)
+    rspec-core (3.13.6)
+      rspec-support (~> 3.13.0)
+    rspec-expectations (3.13.5)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-mocks (3.13.8)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-support (3.13.7)
+    securerandom (0.4.1)
+    sqlite3 (2.6.0)
+      mini_portile2 (~> 2.8.0)
+    sqlite3 (2.6.0-aarch64-linux-gnu)
+    sqlite3 (2.6.0-aarch64-linux-musl)
+    sqlite3 (2.6.0-arm-linux-gnu)
+    sqlite3 (2.6.0-arm-linux-musl)
+    sqlite3 (2.6.0-arm64-darwin)
+    sqlite3 (2.6.0-x86-linux-gnu)
+    sqlite3 (2.6.0-x86-linux-musl)
+    sqlite3 (2.6.0-x86_64-darwin)
+    sqlite3 (2.6.0-x86_64-linux-gnu)
+    sqlite3 (2.6.0-x86_64-linux-musl)
+    thor (1.5.0)
+    timeout (0.6.1)
+    tzinfo (2.0.6)
+      concurrent-ruby (~> 1.0)
+
+PLATFORMS
+  aarch64-linux-gnu
+  aarch64-linux-musl
+  arm-linux-gnu
+  arm-linux-musl
+  arm64-darwin
+  x86-linux-gnu
+  x86-linux-musl
+  x86_64-darwin
+  x86_64-linux-gnu
+  x86_64-linux-musl
+
+DEPENDENCIES
+  activerecord (~> 7.1.0)
+  activesupport (~> 7.1.0)
+  appraisal (~> 2.5)
+  bigdecimal
+  byebug
+  cucumber-ci-environment
+  rake (~> 13.2)
+  rspec (~> 3.0)
+  sanitization!
+  sqlite3 (~> 2.6.0)
+
+BUNDLED WITH
+   2.6.3
diff --git a/gemfiles/rails_7.gemfile b/gemfiles/rails_7.2.gemfile
similarity index 58%
rename from gemfiles/rails_7.gemfile
rename to gemfiles/rails_7.2.gemfile
index 7179ce8..6625a0e 100644
--- a/gemfiles/rails_7.gemfile
+++ b/gemfiles/rails_7.2.gemfile
@@ -6,13 +6,10 @@ gem "rake", "~> 13.2"
 gem "rspec", "~> 3.0"
 gem "appraisal", "~> 2.5"
 gem "cucumber-ci-environment"
-gem "sqlite3", "~> 1.4"
+gem "sqlite3", "~> 2.6.0"
 gem "byebug"
-gem "activerecord", "~> 7.0.1"
-gem "activesupport", "~> 7.0.1"
-gem "mutex_m", "~> 0.3.0"
-gem "base64"
+gem "activerecord", "~> 7.2.0"
+gem "activesupport", "~> 7.2.0"
 gem "bigdecimal"
-gem "concurrent-ruby", "< 1.3.5"
 
 gemspec path: "../"
diff --git a/gemfiles/rails_7.2.gemfile.lock b/gemfiles/rails_7.2.gemfile.lock
new file mode 100644
index 0000000..f34f9a5
--- /dev/null
+++ b/gemfiles/rails_7.2.gemfile.lock
@@ -0,0 +1,108 @@
+PATH
+  remote: ..
+  specs:
+    sanitization (2.0.0)
+      activerecord (>= 7.1)
+      activesupport (>= 7.1)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    activemodel (7.2.3.1)
+      activesupport (= 7.2.3.1)
+    activerecord (7.2.3.1)
+      activemodel (= 7.2.3.1)
+      activesupport (= 7.2.3.1)
+      timeout (>= 0.4.0)
+    activesupport (7.2.3.1)
+      base64
+      benchmark (>= 0.3)
+      bigdecimal
+      concurrent-ruby (~> 1.0, >= 1.3.1)
+      connection_pool (>= 2.2.5)
+      drb
+      i18n (>= 1.6, < 2)
+      logger (>= 1.4.2)
+      minitest (>= 5.1, < 6)
+      securerandom (>= 0.3)
+      tzinfo (~> 2.0, >= 2.0.5)
+    appraisal (2.5.0)
+      bundler
+      rake
+      thor (>= 0.14.0)
+    base64 (0.3.0)
+    benchmark (0.5.0)
+    bigdecimal (4.1.2)
+    byebug (13.0.0)
+      reline (>= 0.6.0)
+    concurrent-ruby (1.3.6)
+    connection_pool (3.0.2)
+    cucumber-ci-environment (13.0.0)
+    diff-lcs (1.6.2)
+    drb (2.2.3)
+    i18n (1.14.8)
+      concurrent-ruby (~> 1.0)
+    io-console (0.8.2)
+    logger (1.7.0)
+    mini_portile2 (2.8.9)
+    minitest (5.27.0)
+    rake (13.4.2)
+    reline (0.6.3)
+      io-console (~> 0.5)
+    rspec (3.13.2)
+      rspec-core (~> 3.13.0)
+      rspec-expectations (~> 3.13.0)
+      rspec-mocks (~> 3.13.0)
+    rspec-core (3.13.6)
+      rspec-support (~> 3.13.0)
+    rspec-expectations (3.13.5)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-mocks (3.13.8)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-support (3.13.7)
+    securerandom (0.4.1)
+    sqlite3 (2.6.0)
+      mini_portile2 (~> 2.8.0)
+    sqlite3 (2.6.0-aarch64-linux-gnu)
+    sqlite3 (2.6.0-aarch64-linux-musl)
+    sqlite3 (2.6.0-arm-linux-gnu)
+    sqlite3 (2.6.0-arm-linux-musl)
+    sqlite3 (2.6.0-arm64-darwin)
+    sqlite3 (2.6.0-x86-linux-gnu)
+    sqlite3 (2.6.0-x86-linux-musl)
+    sqlite3 (2.6.0-x86_64-darwin)
+    sqlite3 (2.6.0-x86_64-linux-gnu)
+    sqlite3 (2.6.0-x86_64-linux-musl)
+    thor (1.5.0)
+    timeout (0.6.1)
+    tzinfo (2.0.6)
+      concurrent-ruby (~> 1.0)
+
+PLATFORMS
+  aarch64-linux-gnu
+  aarch64-linux-musl
+  arm-linux-gnu
+  arm-linux-musl
+  arm64-darwin
+  x86-linux-gnu
+  x86-linux-musl
+  x86_64-darwin
+  x86_64-linux-gnu
+  x86_64-linux-musl
+
+DEPENDENCIES
+  activerecord (~> 7.2.0)
+  activesupport (~> 7.2.0)
+  appraisal (~> 2.5)
+  bigdecimal
+  byebug
+  cucumber-ci-environment
+  rake (~> 13.2)
+  rspec (~> 3.0)
+  sanitization!
+  sqlite3 (~> 2.6.0)
+
+BUNDLED WITH
+   2.6.3
diff --git a/gemfiles/rails_7.gemfile.lock b/gemfiles/rails_7.gemfile.lock
deleted file mode 100644
index 6341616..0000000
--- a/gemfiles/rails_7.gemfile.lock
+++ /dev/null
@@ -1,84 +0,0 @@
-PATH
-  remote: ..
-  specs:
-    sanitization (1.1.4)
-      activerecord
-      activesupport
-
-GEM
-  remote: https://rubygems.org/
-  specs:
-    activemodel (7.0.8.7)
-      activesupport (= 7.0.8.7)
-    activerecord (7.0.8.7)
-      activemodel (= 7.0.8.7)
-      activesupport (= 7.0.8.7)
-    activesupport (7.0.8.7)
-      concurrent-ruby (~> 1.0, >= 1.0.2)
-      i18n (>= 1.6, < 2)
-      minitest (>= 5.1)
-      tzinfo (~> 2.0)
-    appraisal (2.5.0)
-      bundler
-      rake
-      thor (>= 0.14.0)
-    base64 (0.2.0)
-    bigdecimal (3.1.9)
-    byebug (12.0.0)
-    concurrent-ruby (1.3.4)
-    cucumber-ci-environment (10.0.1)
-    diff-lcs (1.6.1)
-    i18n (1.14.7)
-      concurrent-ruby (~> 1.0)
-    mini_portile2 (2.8.8)
-    minitest (5.25.5)
-    mutex_m (0.3.0)
-    rake (13.2.1)
-    rspec (3.13.0)
-      rspec-core (~> 3.13.0)
-      rspec-expectations (~> 3.13.0)
-      rspec-mocks (~> 3.13.0)
-    rspec-core (3.13.3)
-      rspec-support (~> 3.13.0)
-    rspec-expectations (3.13.3)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.13.0)
-    rspec-mocks (3.13.2)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.13.0)
-    rspec-support (3.13.2)
-    sqlite3 (1.7.3)
-      mini_portile2 (~> 2.8.0)
-    thor (1.3.2)
-    tzinfo (2.0.6)
-      concurrent-ruby (~> 1.0)
-
-PLATFORMS
-  aarch64-linux-gnu
-  aarch64-linux-musl
-  arm-linux-gnu
-  arm-linux-musl
-  arm64-darwin
-  x86-linux-gnu
-  x86-linux-musl
-  x86_64-darwin
-  x86_64-linux-gnu
-  x86_64-linux-musl
-
-DEPENDENCIES
-  activerecord (~> 7.0.1)
-  activesupport (~> 7.0.1)
-  appraisal (~> 2.5)
-  base64
-  bigdecimal
-  byebug
-  concurrent-ruby (< 1.3.5)
-  cucumber-ci-environment
-  mutex_m (~> 0.3.0)
-  rake (~> 13.2)
-  rspec (~> 3.0)
-  sanitization!
-  sqlite3 (~> 1.4)
-
-BUNDLED WITH
-   2.6.3
diff --git a/gemfiles/rails_8.gemfile.lock b/gemfiles/rails_8.gemfile.lock
index bec8e3a..0fb3ba7 100644
--- a/gemfiles/rails_8.gemfile.lock
+++ b/gemfiles/rails_8.gemfile.lock
@@ -1,9 +1,9 @@
 PATH
   remote: ..
   specs:
-    sanitization (1.1.4)
-      activerecord
-      activesupport
+    sanitization (2.0.0)
+      activerecord (>= 7.1)
+      activesupport (>= 7.1)
 
 GEM
   remote: https://rubygems.org/
@@ -43,7 +43,11 @@ GEM
     i18n (1.14.7)
       concurrent-ruby (~> 1.0)
     logger (1.7.0)
-    minitest (5.25.5)
+    mini_portile2 (2.8.9)
+    minitest (6.0.5)
+      drb (~> 2.0)
+      prism (~> 1.5)
+    prism (1.9.0)
     rake (13.2.1)
     rspec (3.13.0)
       rspec-core (~> 3.13.0)
@@ -59,6 +63,8 @@ GEM
       rspec-support (~> 3.13.0)
     rspec-support (3.13.2)
     securerandom (0.4.1)
+    sqlite3 (2.6.0)
+      mini_portile2 (~> 2.8.0)
     sqlite3 (2.6.0-aarch64-linux-gnu)
     sqlite3 (2.6.0-aarch64-linux-musl)
     sqlite3 (2.6.0-arm-linux-gnu)
@@ -93,7 +99,6 @@ DEPENDENCIES
   appraisal (~> 2.5)
   bigdecimal
   byebug
-  concurrent-ruby (< 1.3.5)
   cucumber-ci-environment
   rake (~> 13.2)
   rspec (~> 3.0)
diff --git a/lib/sanitization/active_record_extension.rb b/lib/sanitization/active_record_extension.rb
index f6fb125..f4d3ca4 100644
--- a/lib/sanitization/active_record_extension.rb
+++ b/lib/sanitization/active_record_extension.rb
@@ -5,6 +5,52 @@ def self.append_features(base)
       base.extend(ClassMethods)
     end
 
+    # Taken from `strip_attributes`: https://github.com/rmm5t/strip_attributes/blob/master/lib/strip_attributes.rb
+    # Unicode invisible and whitespace characters. The POSIX character class
+    # [:space:] corresponds to the Unicode class Z ("separator"). We also
+    # include the following characters from Unicode class C ("control"), which
+    # are spaces or invisible characters that make no sense at the start or end
+    # of a string:
+    #   U+180E MONGOLIAN VOWEL SEPARATOR
+    #   U+200B ZERO WIDTH SPACE
+    #   U+200C ZERO WIDTH NON-JOINER
+    #   U+200D ZERO WIDTH JOINER
+    #   U+2060 WORD JOINER
+    #   U+FEFF ZERO WIDTH NO-BREAK SPACE
+    MULTIBYTE_WHITE = "\u180E\u200B\u200C\u200D\u2060\uFEFF".freeze
+    MULTIBYTE_BLANK = /[[:blank:]#{MULTIBYTE_WHITE}]/.freeze
+    MULTIBYTE_SUPPORTED = "\u0020" == " "
+
+    def self.format_value(value, settings)
+      return value unless value.is_a?(String)
+
+      v = value.dup
+      v.strip! if value_or_default(settings, :strip)
+
+      if value_or_default(settings, :collapse)
+        if MULTIBYTE_SUPPORTED && Encoding.compatible?(v, MULTIBYTE_BLANK)
+          v.gsub!(/#{MULTIBYTE_BLANK}+/, " ")
+        else
+          v.squeeze!(" ")
+        end
+      end
+
+      return nil if value_or_default(settings, :nullify) && v.empty? && settings[:null]
+
+      case_method = value_or_default(settings, :case)
+      v = v.send(case_method) if case_method && case_method != :none
+
+      v
+    end
+
+    def self.value_or_default(settings, transform)
+      if settings[transform].nil?
+        Sanitization.configuration[transform]
+      else
+        settings[transform]
+      end
+    end
+
     module ClassMethods
       attr_accessor :sanitization__store
 
@@ -51,84 +97,21 @@ def sanitizes(options = {})
             unless @valid_case_methods.include?(options[:case]) || options[:case] == :none
         end
 
+        klass = self
         columns_to_format.each do |col|
-          self.sanitization__store[col.name] ||= {}
+          fresh = !self.sanitization__store.key?(col.name)
+          self.sanitization__store[col.name] ||= { null: col.null }
           self.sanitization__store[col.name].merge!(options.slice(:case, :strip, :collapse, :nullify))
-        end
-
-        class_eval <<-EOV
-          include Sanitization::ActiveRecordExtension::InstanceMethods
-          before_save :sanitization__format_strings
-        EOV
-      end
-      alias sanitization sanitizes
-    end # module ClassMethods
-
-    module InstanceMethods
-        # Taken from `strip_attributes`: https://github.com/rmm5t/strip_attributes/blob/master/lib/strip_attributes.rb
-        # Unicode invisible and whitespace characters. The POSIX character class
-        # [:space:] corresponds to the Unicode class Z ("separator"). We also
-        # include the following characters from Unicode class C ("control"), which
-        # are spaces or invisible characters that make no sense at the start or end
-        # of a string:
-        #   U+180E MONGOLIAN VOWEL SEPARATOR
-        #   U+200B ZERO WIDTH SPACE
-        #   U+200C ZERO WIDTH NON-JOINER
-        #   U+200D ZERO WIDTH JOINER
-        #   U+2060 WORD JOINER
-        #   U+FEFF ZERO WIDTH NO-BREAK SPACE
-        MULTIBYTE_WHITE = "\u180E\u200B\u200C\u200D\u2060\uFEFF".freeze
-        MULTIBYTE_SPACE = /[[:space:]#{MULTIBYTE_WHITE}]/.freeze
-        MULTIBYTE_BLANK = /[[:blank:]#{MULTIBYTE_WHITE}]/.freeze
-        MULTIBYTE_SUPPORTED = "\u0020" == " "
-
-      private
-
-      def sanitization__format_strings
-        return unless self.class.sanitization__store
 
-        class_formatting = self.class.sanitization__store
-        class_formatting.each_pair do |col_name, col_formatting|
-          sanitization__format_column(col_name, col_formatting)
-        end
-      end
-
-      def sanitization__format_column(col_name, col_formatting)
-        return unless self[col_name].is_a?(String)
-
-        self[col_name].strip! if value_or_default(col_formatting, :strip)
-
-        if value_or_default(col_formatting, :collapse)
-          if MULTIBYTE_SUPPORTED && Encoding.compatible?(self[col_name], MULTIBYTE_BLANK)
-            self[col_name].gsub!(/#{MULTIBYTE_BLANK}+/, " ")
-          else
-            self[col_name].squeeze!(" ")
+          if fresh
+            col_name = col.name
+            normalizes col_name.to_sym, with: ->(value) {
+              Sanitization::ActiveRecordExtension.format_value(value, klass.sanitization__store[col_name])
+            }
           end
         end
-
-        if value_or_default(col_formatting, :nullify) && !self[col_name].nil? && self[col_name].to_s.empty? && \
-          self.class.columns.select { |c| c.name == col_name }.first.null
-          return self[col_name] = nil
-        end
-
-        case_formatting_method = value_or_default(col_formatting, :case)
-        if !case_formatting_method.nil? && case_formatting_method != :none
-          self[col_name] = self[col_name].send(case_formatting_method)
-        end
-
-        self[col_name]
       end
-
-      def value_or_default(col_formatting, transform)
-        if col_formatting[transform].nil?
-          Sanitization.configuration[transform]
-        else
-          col_formatting[transform]
-        end
-      end
-
-
-    end # module InstanceMethods
+      alias sanitization sanitizes
+    end # module ClassMethods
   end # module ActiveRecordExt
 end # module Sanitization
-
diff --git a/lib/sanitization/version.rb b/lib/sanitization/version.rb
index 6296627..1775452 100644
--- a/lib/sanitization/version.rb
+++ b/lib/sanitization/version.rb
@@ -1,3 +1,3 @@
 module Sanitization
-  VERSION = "1.2.0"
+  VERSION = "2.0.0"
 end
diff --git a/sanitization.gemspec b/sanitization.gemspec
index a6bb44e..a3ea99a 100644
--- a/sanitization.gemspec
+++ b/sanitization.gemspec
@@ -10,7 +10,7 @@ Gem::Specification.new do |spec|
   spec.description   = %q{Sanitization makes it easy to store slightly cleaner strings to your database.}
   spec.homepage      = "https://github.com/cmer/sanitization"
   spec.license       = "MIT"
-  spec.required_ruby_version = Gem::Requirement.new(">= 2.7.0")
+  spec.required_ruby_version = Gem::Requirement.new(">= 3.2.0")
 
   spec.metadata["allowed_push_host"] = "https://rubygems.org"
 
@@ -26,9 +26,8 @@ Gem::Specification.new do |spec|
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
-  spec.add_runtime_dependency "activerecord"
-  spec.add_runtime_dependency "activesupport"
+  spec.add_runtime_dependency "activerecord", ">= 7.1"
+  spec.add_runtime_dependency "activesupport", ">= 7.1"
   spec.add_development_dependency "appraisal", "~> 2.5"
-  spec.add_development_dependency "concurrent-ruby", "< 1.3.5"
   spec.add_development_dependency "sqlite3", "~> 2.6.0"
 end
diff --git a/spec/sanitization_spec.rb b/spec/sanitization_spec.rb
index 45c7484..5dbe61e 100644
--- a/spec/sanitization_spec.rb
+++ b/spec/sanitization_spec.rb
@@ -94,4 +94,92 @@ class Person < ActiveRecord::Base
       end
     end
   end
+
+  context "Assignment-time semantics (normalizes integration)" do
+    before(:all) { Sanitization.simple_defaults! }
+
+    let(:base_attrs) {
+      { first_name: "John", last_name: "Smith", city: "NYC",
+        email: "user@example.org", do_not_collapse: "x" }
+    }
+
+    it "normalizes on assignment, before save" do
+      person = Person.new
+      person.first_name = " john "
+      expect(person.first_name).to eq("JOHN")
+      expect(person.persisted?).to be false
+    end
+
+    it "normalizes attributes passed to .new" do
+      person = Person.new(first_name: "  jane  ", email: "  USER@X.ORG  ")
+      expect(person.first_name).to eq("JANE")
+      expect(person.email).to eq("user@x.org")
+    end
+
+    it "leaves nil values as nil (apply_to_nil: false default)" do
+      person = Person.new(first_name: nil)
+      expect(person.first_name).to be_nil
+    end
+
+    it "is idempotent — normalizing a normalized value is a no-op" do
+      once  = Person.normalize_value_for(:email, "  USER@X.ORG  ")
+      twice = Person.normalize_value_for(:email, once)
+      expect(once).to eq("user@x.org")
+      expect(twice).to eq(once)
+    end
+
+    it "normalizes hash conditions in .where" do
+      Person.create!(base_attrs.merge(email: "raw@example.org"))
+      expect(Person.where(email: "  RAW@EXAMPLE.ORG  ").count).to be >= 1
+    end
+
+    it "normalizes the lookup value in .find_by" do
+      Person.create!(base_attrs.merge(email: "lookup@example.org"))
+      expect(Person.find_by(email: "  LOOKUP@EXAMPLE.ORG  ")).not_to be_nil
+    end
+
+    it "does NOT auto-normalize legacy rows on plain save" do
+      person = Person.create!(base_attrs.merge(email: "legacy@example.org"))
+      ActiveRecord::Base.connection.execute(
+        "UPDATE people SET email = '  LEGACY-RAW@X.ORG  ' WHERE id = #{person.id}"
+      )
+      person.reload
+      expect(person.email).to eq("  LEGACY-RAW@X.ORG  ") # reload does not normalize
+      person.last_name = "OTHER"
+      person.save!
+      person.reload
+      expect(person.email).to eq("  LEGACY-RAW@X.ORG  ") # unrelated save did not heal it
+    end
+
+    it "migrates legacy rows on demand via normalize_attribute" do
+      person = Person.create!(base_attrs.merge(email: "migrate@example.org"))
+      ActiveRecord::Base.connection.execute(
+        "UPDATE people SET email = '  MIGRATE-RAW@X.ORG  ' WHERE id = #{person.id}"
+      )
+      person.reload
+      person.normalize_attribute(:email)
+      person.save!
+      person.reload
+      expect(person.email).to eq("migrate-raw@x.org")
+    end
+
+    it "re-normalizes values mutated in place before validation" do
+      person = Person.new(base_attrs)
+      person.email << "   "  # mutate in place
+      person.valid?          # before_validation hook re-normalizes
+      expect(person.email).to eq("user@example.org")
+    end
+
+    it "runs validations against normalized values" do
+      validating = Class.new(Person) do
+        def self.name; "ValidatingPerson"; end
+        validates_each :email do |record, attr, value|
+          record.errors.add(attr, "must be lowercase") if value && value != value.downcase
+        end
+      end
+      person = validating.new(base_attrs.merge(email: "  RAW@X.ORG  "))
+      expect(person.email).to eq("raw@x.org")
+      expect(person.valid?).to be true
+    end
+  end
 end