diff --git a/README.md b/README.md
index 2b0c7ec3..9638b0b5 100644
--- a/README.md
+++ b/README.md
@@ -465,3 +465,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 7. Reverse Integer                                | [Link](https://leetcode.com/problems/reverse-integer/)                                | [Link](./lib/medium/7_reverse_integer.rb)                                |
 | 8. String to Integer (atoi)                       | [Link](https://leetcode.com/problems/string-to-integer-atoi/)                         | [Link](./lib/medium/8_string_to_integer_atoi.rb)                         |
 | 11. Container With Most Water                     | [Link](https://leetcode.com/problems/container-with-most-water/)                      | [Link](./lib/medium/11_container_with_most_water.rb)                     |
+| 12. Integer to Roman                              | [Link](https://leetcode.com/problems/integer-to-roman/)                               | [Link](./lib/medium/12_integer_to_roman.rb)                              |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index b8c03a5f..6ee7ffaa 100644
--- a/leetcode-ruby.gemspec
+++ b/leetcode-ruby.gemspec
@@ -5,7 +5,7 @@ require 'English'
 ::Gem::Specification.new do |s|
   s.required_ruby_version = '>= 3.0'
   s.name = 'leetcode-ruby'
-  s.version = '5.9.9'
+  s.version = '6.0.0'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[bin/leetcode-ruby README.md LICENSE]
   s.executable = 'leetcode-ruby'
diff --git a/lib/medium/12_integer_to_roman.rb b/lib/medium/12_integer_to_roman.rb
new file mode 100644
index 00000000..397aab21
--- /dev/null
+++ b/lib/medium/12_integer_to_roman.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: false
+
+# https://leetcode.com/problems/integer-to-roman/
+# @param {Integer} num
+# @return {String}
+def int_to_roman(num)
+  roman_numbers = {
+    1000 => 'M',
+    900 => 'CM',
+    500 => 'D',
+    400 => 'CD',
+    100 => 'C',
+    90 => 'XC',
+    50 => 'L',
+    40 => 'XL',
+    10 => 'X',
+    9 => 'IX',
+    5 => 'V',
+    4 => 'IV',
+    1 => 'I'
+  }
+
+  result = ''
+  roman_numbers.each do |value, symbol|
+    while num >= value
+      result << symbol
+      num -= value
+    end
+  end
+
+  result
+end
diff --git a/test/medium/test_12_integer_to_roman.rb b/test/medium/test_12_integer_to_roman.rb
new file mode 100644
index 00000000..e273c801
--- /dev/null
+++ b/test/medium/test_12_integer_to_roman.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/12_integer_to_roman'
+require 'minitest/autorun'
+
+class IntegerToRomanTest < ::Minitest::Test
+  def test_default
+    assert_equal('MMMDCCXLIX', int_to_roman(3749))
+    assert_equal('LVIII', int_to_roman(58))
+    assert_equal('MCMXCIV', int_to_roman(1994))
+  end
+end