diff --git a/changelog.md b/changelog.md
index 10c95f27..c1129828 100644
--- a/changelog.md
+++ b/changelog.md
@@ -11,8 +11,11 @@ Removed features:
 
 Internal improvements:
 
+* Require base64 for ruby 3.4 support ([#688](https://github.com/arsduo/koala/pull/688))
+
 Testing improvements:
 
+* Fix CI for ruby 3.4 ([#688](https://github.com/arsduo/koala/pull/688))
 * Add latest rubies to CI ([#687](https://github.com/arsduo/koala/pull/687))
 
 Others:
diff --git a/koala.gemspec b/koala.gemspec
index cd7b2587..5c16e6f1 100644
--- a/koala.gemspec
+++ b/koala.gemspec
@@ -28,4 +28,5 @@ Gem::Specification.new do |gem|
   gem.add_runtime_dependency("addressable")
   gem.add_runtime_dependency("json", ">= 1.8")
   gem.add_runtime_dependency("rexml")
+  gem.add_runtime_dependency("base64")
 end