diff --git a/activemodel/lib/active_model/attribute_methods.rb b/activemodel/lib/active_model/attribute_methods.rb
index 8f855958c6..977a101277 100644
--- a/activemodel/lib/active_model/attribute_methods.rb
+++ b/activemodel/lib/active_model/attribute_methods.rb
@@ -235,10 +235,6 @@ module ActiveModel
     # It's also possible to instantiate related objects, so a Client class belonging to the clients
     # table with a +master_id+ foreign key can instantiate master through Client#master.
     def method_missing(method_id, *args, &block)
-      if method_id == :to_ary || method_id == :to_str
-        raise NoMethodError, "undefined method `#{method_id}' for #{inspect}:#{self.class}"
-      end
-
       method_name = method_id.to_s
       if match = match_attribute_method?(method_name)
         guard_private_attribute_method!(method_name, args)