diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 12adec8..0a0883c 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -25,6 +25,7 @@ jobs:
         - "3.0"
         - "3.1"
         - "3.2"
+        - "3.3"
         - truffleruby-head
         gemfile:
         - gemfiles/rails_3_0.gemfile
@@ -174,6 +175,24 @@ jobs:
           gemfile: gemfiles/rails_5_1.gemfile
         - ruby: "3.2"
           gemfile: gemfiles/rails_5_2.gemfile
+        - ruby: "3.3"
+          gemfile: gemfiles/rails_3_0.gemfile
+        - ruby: "3.3"
+          gemfile: gemfiles/rails_3_1.gemfile
+        - ruby: "3.3"
+          gemfile: gemfiles/rails_3_2.gemfile
+        - ruby: "3.3"
+          gemfile: gemfiles/rails_4_0.gemfile
+        - ruby: "3.3"
+          gemfile: gemfiles/rails_4_1.gemfile
+        - ruby: "3.3"
+          gemfile: gemfiles/rails_4_2.gemfile
+        - ruby: "3.3"
+          gemfile: gemfiles/rails_5_0.gemfile
+        - ruby: "3.3"
+          gemfile: gemfiles/rails_5_1.gemfile
+        - ruby: "3.3"
+          gemfile: gemfiles/rails_5_2.gemfile
         - ruby: truffleruby-head
           gemfile: gemfiles/rails_3_0.gemfile
         - ruby: truffleruby-head
diff --git a/CHANGELOG.md b/CHANGELOG.md
index afde742..199259c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# ActiveAttr (Unreleased)
+
+* ActiveAttr now supports Ruby 3.3
+
 # ActiveAttr 0.16.0 (October 30, 2023)
 
 * ActiveAttr now supports Ruby 3.1
diff --git a/active_attr.gemspec b/active_attr.gemspec
index 4cc5fb9..9e797e2 100644
--- a/active_attr.gemspec
+++ b/active_attr.gemspec
@@ -27,7 +27,7 @@ Gem::Specification.new do |gem|
   gem.add_runtime_dependency "activesupport", ">= 3.0.2", "< 7.2"
 
   gem.add_development_dependency "bundler"
-  gem.add_development_dependency "factory_bot",  "< 5.0"
+  gem.add_development_dependency "factory_bot",  "< 7.0"
   gem.add_development_dependency "minitest"
   gem.add_development_dependency "rake",         ">= 0.9.0", "< 13.1"
   gem.add_development_dependency "rspec",        "~> 3.0"