diff --git a/lib/signature.rb b/lib/signature.rb
index 13659ec..c00075a 100644
--- a/lib/signature.rb
+++ b/lib/signature.rb
@@ -1,5 +1,4 @@
 require 'hmac-sha2'
-require 'base64'
 
 module Signature
   class AuthenticationError < RuntimeError; end