diff --git a/README.md b/README.md
index 1c20faff..ff9aae22 100644
--- a/README.md
+++ b/README.md
@@ -676,6 +676,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 1302. Deepest Leaves Sum                                         | [Link](https://leetcode.com/problems/deepest-leaves-sum/)                                          | [Link](./lib/medium/1302_deepest_leaves_sum.rb)                                         | [Link](./test/medium/test_1302_deepest_leaves_sum.rb)                                         |
 | 1305. All Elements in Two Binary Search Trees                    | [Link](https://leetcode.com/problems/all-elements-in-two-binary-search-trees/)                     | [Link](./lib/medium/1305_all_elements_in_two_binary_search_trees.rb)                    | [Link](./test/medium/test_1305_all_elements_in_two_binary_search_trees.rb)                    |
 | 1310. XOR Queries of a Subarray                                  | [Link](https://leetcode.com/problems/xor-queries-of-a-subarray/)                                   | [Link](./lib/medium/1310_xor_queries_of_a_subarray.rb)                                  | [Link](./test/medium/test_1310_xor_queries_of_a_subarray.rb)                                  |
+| 1315. Sum of Nodes with Even-Valued Grandparent                  | [Link](https://leetcode.com/problems/sum-of-nodes-with-even-valued-grandparent/)                   | [Link](./lib/medium/1315_sum_of_nodes_with_even_valued_grandparent.rb)                  | [Link](./test/medium/test_1315_sum_of_nodes_with_even_valued_grandparent.rb)                  |
 | 1400. Construct K Palindrome Strings                             | [Link](https://leetcode.com/problems/construct-k-palindrome-strings/)                              | [Link](./lib/medium/1400_construct_k_palindrome_strings.rb)                             | [Link](./test/medium/test_1400_construct_k_palindrome_strings.rb)                             |
 | 2116. Check if a Parentheses String Can Be Valid                 | [Link](https://leetcode.com/problems/check-if-a-parentheses-string-can-be-valid/)                  | [Link](./lib/medium/2116_check_if_a_parentheses_string_can_be_valid.rb)                 | [Link](./test/medium/test_2116_check_if_a_parentheses_string_can_be_valid.rb)                 |
 | 2425. Bitwise XOR of All Pairings                                | [Link](https://leetcode.com/problems/bitwise-xor-of-all-pairings/)                                 | [Link](./lib/medium/2425_bitwise_xor_of_all_pairings.rb)                                | [Link](./test/medium/test_2425_bitwise_xor_of_all_pairings.rb)                                |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index 58e58619..708c7692 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 = '8.4.3'
+  s.version = '8.4.4'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'
diff --git a/lib/medium/1315_sum_of_nodes_with_even_valued_grandparent.rb b/lib/medium/1315_sum_of_nodes_with_even_valued_grandparent.rb
new file mode 100644
index 00000000..52104946
--- /dev/null
+++ b/lib/medium/1315_sum_of_nodes_with_even_valued_grandparent.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/sum-of-nodes-with-even-valued-grandparent/
+# @param {TreeNode} root
+# @return {Integer}
+def sum_even_grandparent(root)
+  @sum = 0
+  sum_for_even_grandparent(root, nil, nil)
+
+  @sum
+end
+
+private
+
+# @param {TreeNode} curr
+# @param {TreeNode} parent
+# @param {TreeNode} grandparent
+# @return {Void}
+def sum_for_even_grandparent(curr, parent, grandparent)
+  return unless curr
+
+  @sum += curr.val if grandparent&.val&.even?
+
+  sum_for_even_grandparent(curr.left, curr, parent)
+  sum_for_even_grandparent(curr.right, curr, parent)
+end
diff --git a/test/medium/test_1315_sum_of_nodes_with_even_valued_grandparent.rb b/test/medium/test_1315_sum_of_nodes_with_even_valued_grandparent.rb
new file mode 100644
index 00000000..059150d1
--- /dev/null
+++ b/test/medium/test_1315_sum_of_nodes_with_even_valued_grandparent.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/common/binary_tree'
+require_relative '../../lib/medium/1315_sum_of_nodes_with_even_valued_grandparent'
+require 'minitest/autorun'
+
+class SumOfNodesWithEvenValuedGrandparentTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      18,
+      sum_even_grandparent(
+        ::TreeNode.build_tree(
+          [6, 7, 8, 2, 7, 1, 3, 9, nil, 1, 4, nil, nil, nil, 5]
+        )
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      0,
+      sum_even_grandparent(
+        ::TreeNode.build_tree(
+          [1]
+        )
+      )
+    )
+  end
+end