diff --git a/activerecord/lib/active_record/dynamic_scope_match.rb b/activerecord/lib/active_record/dynamic_scope_match.rb
index f796ba669a..15f65be6bc 100644
--- a/activerecord/lib/active_record/dynamic_scope_match.rb
+++ b/activerecord/lib/active_record/dynamic_scope_match.rb
@@ -1,4 +1,11 @@
module ActiveRecord
+
+ # = Active Record Dynamic Scope Match
+ #
+ # Provides dynamic attribute-based scopes such as scoped_by_price(4.99)
+ # if, for example, the Product has an attribute with that name. You can
+ # chain more scoped_by_* methods after the other. It acts like a named
+ # scope except that it's dynamic.
class DynamicScopeMatch
def self.match(method)
ds_match = self.new(method)