diff --git a/.github/workflows/default.yml b/.github/workflows/default.yml
index 22248c0..5aa834a 100644
--- a/.github/workflows/default.yml
+++ b/.github/workflows/default.yml
@@ -13,19 +13,19 @@ jobs:
   preflight_check:
     name: Preflight Check
     runs-on: ubuntu-latest
-    # do a matrix for ACTIVERECORD_VERSION of 6.1 and 7.0
+    # do a matrix for ACTIVERECORD_VERSION of 7.2 and 8.1
     strategy:
       matrix:
         activerecord_version:
-          - 6.1
-          - 7.0
+          - 7.2
+          - 8.1
     steps:
       # Need to fetch all refs, so we can check if the version has been bumped
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           fetch-depth: 0
 
-      - uses: ruby/setup-ruby@v1
+      - uses: ruby/setup-ruby@97ecb7b512899eb71ab1bf2310a624c6f1589ac6 # v1.308.0
         with:
           bundler-cache: true
         env:
diff --git a/.ruby-version b/.ruby-version
index 6ebad14..7bcbb38 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-3.1.2
\ No newline at end of file
+3.4.9
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 52ef721..f08eb31 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # attr_encrypted #
 
+## 3.2.0 ##
+* Changed: Ruby minimum version raised to 3.4.x.
+* Changed: CI test matrix updated to ActiveRecord 7.2 and 8.1. ActiveRecord 6.x is no longer included in the test matrix and is not actively supported.
+* Fixed: Removed Rails 4.0.x minitest compatibility shim that caused a `NameError` on modern minitest.
+* Fixed: Guarded `ActiveSupport::Deprecation` calls that were removed in Rails 7.1+.
+* Fixed: Replaced `stub` usage in tests with `define_singleton_method` for minitest 6 compatibility.
+
 ## 3.1.0 ##
 * Added: Abitilty to encrypt empty values. (@tamird)
 * Added: MIT license
diff --git a/lib/attr_encrypted/version.rb b/lib/attr_encrypted/version.rb
index 723ebe9..d2502d7 100644
--- a/lib/attr_encrypted/version.rb
+++ b/lib/attr_encrypted/version.rb
@@ -4,7 +4,7 @@ module AttrEncrypted
   # Contains information about this gem's version
   module Version
     MAJOR = 3
-    MINOR = 1
+    MINOR = 2
     PATCH = 0
 
     # Returns a version string by joining <tt>MAJOR</tt>, <tt>MINOR</tt>, and <tt>PATCH</tt> with <tt>'.'</tt>
diff --git a/test/attr_encrypted_test.rb b/test/attr_encrypted_test.rb
index 0df966a..2903b73 100644
--- a/test/attr_encrypted_test.rb
+++ b/test/attr_encrypted_test.rb
@@ -482,9 +482,8 @@ def test_encrypted_attributes_state_is_not_shared
   def test_should_not_by_default_generate_key_when_attribute_is_empty
     user = User.new
     calls = 0
-    user.stub(:secret_key, lambda { calls += 1; SECRET_KEY }) do
-      user.ssn
-    end
+    user.define_singleton_method(:secret_key) { calls += 1; SECRET_KEY }
+    user.ssn
     assert_equal 0, calls
   end
 end
diff --git a/test/legacy_active_record_test.rb b/test/legacy_active_record_test.rb
index 8023185..8c1f3da 100644
--- a/test/legacy_active_record_test.rb
+++ b/test/legacy_active_record_test.rb
@@ -29,9 +29,9 @@ class LegacyPerson < ActiveRecord::Base
   attr_encrypted :email, :key => 'a secret key'
   attr_encrypted :credentials, :key => Proc.new { |user| Encryptor.encrypt(:value => user.salt, :key => 'some private key', insecure_mode: true, algorithm: 'aes-256-cbc') }, :marshal => true
 
-  ActiveSupport::Deprecation.silenced = true
+  ActiveSupport::Deprecation.silenced = true if defined?(ActiveSupport::Deprecation) && ActiveSupport::Deprecation.respond_to?(:silenced=)
   def after_initialize; end
-  ActiveSupport::Deprecation.silenced = false
+  ActiveSupport::Deprecation.silenced = false if defined?(ActiveSupport::Deprecation) && ActiveSupport::Deprecation.respond_to?(:silenced=)
 
   after_initialize :initialize_salt_and_credentials
 
diff --git a/test/test_helper.rb b/test/test_helper.rb
index f82e632..e5b0f9e 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -2,15 +2,10 @@
 
 require 'minitest/autorun'
 
-# Rails 4.0.x pins to an old minitest
-unless defined?(MiniTest::Test)
-  MiniTest::Test = MiniTest::Unit::TestCase
-end
-
 require 'active_record'
 require 'digest/sha2'
 require 'sequel'
-ActiveSupport::Deprecation.behavior = :raise
+ActiveSupport::Deprecation.behavior = :raise if defined?(ActiveSupport::Deprecation) && ActiveSupport::Deprecation.respond_to?(:behavior=)
 
 $:.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
 $:.unshift(File.dirname(__FILE__))