diff --git a/lib/http/cookie.rb b/lib/http/cookie.rb
index d39fa34..fea518f 100644
--- a/lib/http/cookie.rb
+++ b/lib/http/cookie.rb
@@ -473,6 +473,9 @@ class HTTP::Cookie
     @expires = t
   end
 
+  alias expires_at expires
+  alias expires_at= expires=
+
   attr_reader :max_age
 
   # See #max_age.