diff --git a/activemodel/lib/active_model/attribute_methods.rb b/activemodel/lib/active_model/attribute_methods.rb
index b5b50847c2..6e93fdd625 100644
--- a/activemodel/lib/active_model/attribute_methods.rb
+++ b/activemodel/lib/active_model/attribute_methods.rb
@@ -314,7 +314,7 @@ module ActiveModel
           RUBY
         end
 
-        class AttributeMethodMatcher
+        class AttributeMethodMatcher #:nodoc:
           attr_reader :prefix, :suffix, :method_missing_target
 
           AttributeMethodMatch = Struct.new(:target, :attr_name, :method_name)