diff --git a/lib/luhn/civic_number.rb b/lib/luhn/civic_number.rb
index e9a08c1..bbabb19 100644
--- a/lib/luhn/civic_number.rb
+++ b/lib/luhn/civic_number.rb
@@ -1,5 +1,4 @@
 # encoding: UTF-8
-require 'ostruct'
 module Luhn
   class CivicNumber
     attr_reader :value
@@ -33,11 +32,11 @@ def male?
     end
 
     def birth_date
-      OpenStruct.new({
-        :year  => value[0...2].to_i,
-        :month => value[2...4].to_i,
-        :day   => value[4...6].to_i
-      })
+      Data.define(:year, :month, :day).new(
+        value[0...2].to_i,
+        value[2...4].to_i,
+        value[4...6].to_i
+      )
     end
 
     def formatted
diff --git a/luhn.gemspec b/luhn.gemspec
index 5cab56b..61a5f52 100644
--- a/luhn.gemspec
+++ b/luhn.gemspec
@@ -12,7 +12,7 @@ Gem::Specification.new do |s|
   s.platform     = Gem::Platform::RUBY
   s.files        = Dir.glob("{lib,spec}/**/*") + %w[LICENSE README.rdoc]
 
-  s.add_dependency 'ostruct', '~> 0' if Gem.ruby_version >= Gem::Version.new("3.4.0")
+  s.required_ruby_version = '>= 3.2'
 
   s.add_development_dependency 'minitest', '~> 2.6.0'
 end