diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 5d1c4ba..7f50dc4 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -16,8 +16,27 @@ jobs:
       matrix:
         ruby-version:
           - 2.7
+          - 3.0
+          - 3.1
+          - 3.2
         active-record-version:
-          - 5.2.0
+          - 6.0.0
+          - 6.1.0
+          - 7.0.0
+          - 7.1.0
+        exclude:
+          - ruby-version: 3.2
+            active-record-version: 6.0.0
+          - ruby-version: 3.2
+            active-record-version: 6.1.0
+          - ruby-version: 3.2
+            active-record-version: 7.0.0
+          - ruby-version: 3.1
+            active-record-version: 6.0.0
+          - ruby-version: 3.1
+            active-record-version: 6.1.0
+          - ruby-version: 3.0
+            active-record-version: 6.0.0
     env:
       ACTIVE_RECORD_VERSION: "${{ matrix.active-record-version }}"
     steps:
diff --git a/.gitignore b/.gitignore
index 9aa8d59..d82e0c1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -24,6 +24,8 @@ build/
 /.bundle/
 /lib/bundler/man/
 
+Gemfile.lock
+
 # for a library or gem, you might want to ignore these files since the code is
 # intended to run in multiple environments; otherwise, check them in:
 # Gemfile.lock
diff --git a/.ruby-version b/.ruby-version
index 49cdd66..0aec50e 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-2.7.6
+3.1.4
diff --git a/Gemfile b/Gemfile
index bb44130..41793ee 100644
--- a/Gemfile
+++ b/Gemfile
@@ -9,7 +9,7 @@ ar = case ar_version
 when "master"
   { github: "rails/rails" }
 when "default"
-  ">= 5.2"
+  ">= 6.0"
 else
   "~> #{ar_version}"
 end
diff --git a/dev.yml b/dev.yml
index 33f880f..06b7282 100644
--- a/dev.yml
+++ b/dev.yml
@@ -2,7 +2,7 @@
 version: "2.0"
 
 setup:
-  ruby: 2.7.6
+  ruby: 3.1.4
   bundler: 2.4.21
 
 commands:
diff --git a/inheritance_integer_type.gemspec b/inheritance_integer_type.gemspec
index a58ed2a..06fc8d9 100644
--- a/inheritance_integer_type.gemspec
+++ b/inheritance_integer_type.gemspec
@@ -22,6 +22,6 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rake"
   spec.add_development_dependency "rspec"
   spec.add_development_dependency "activerecord", ">= 5.2"
-  spec.add_development_dependency "sqlite3", "~> 1.3.6"
+  spec.add_development_dependency "sqlite3", "~> 1.4"
   spec.add_development_dependency "pry"
 end
diff --git a/lib/inheritance_integer_type/extensions.rb b/lib/inheritance_integer_type/extensions.rb
index 9fffb5c..afaf712 100644
--- a/lib/inheritance_integer_type/extensions.rb
+++ b/lib/inheritance_integer_type/extensions.rb
@@ -13,7 +13,7 @@ def find_sti_class(type_name)
         else
           begin
             if store_full_sti_class
-              ActiveSupport::Dependencies.constantize(lookup)
+              lookup.constantize
             else
               compute_type(lookup)
             end
diff --git a/spec/inheritance_integer_type_spec.rb b/spec/inheritance_integer_type_spec.rb
index 854882f..c09ccff 100644
--- a/spec/inheritance_integer_type_spec.rb
+++ b/spec/inheritance_integer_type_spec.rb
@@ -48,7 +48,7 @@
     describe "Has many associations" do
       let(:other) { Other.create }
       before do
-        [base, left, deep].each{|a| a.update_attributes(other: other) }
+        [base, left, deep].each{|a| a.update_attribute(:other, other) }
       end
       subject { other }
       it "properly finds the classes through the association" do
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 307170d..b003f0e 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -9,7 +9,7 @@
 
 RSpec.configure do |config|
   config.before(:suite) do
-    ActiveRecord::MigrationContext.new("#{File.dirname(__FILE__)}/support/migrations").migrate
+    ActiveRecord::MigrationContext.new("#{File.dirname(__FILE__)}/support/migrations", ::ActiveRecord::SchemaMigration).migrate
   end
 
   # No need to return the run the down migration after the test