diff --git a/async-dns.gemspec b/async-dns.gemspec
index 923fb76..0848816 100644
--- a/async-dns.gemspec
+++ b/async-dns.gemspec
@@ -24,6 +24,7 @@ Gem::Specification.new do |spec|
 	spec.files = Dir.glob(['{lib}/**/*', '*.md'], File::FNM_DOTMATCH, base: __dir__)
 	
 	spec.required_ruby_version = ">= 3.1"
-	
+
+  spec.add_dependency "base64"
 	spec.add_dependency "io-endpoint"
 end