diff --git a/lib/active_interaction/grouped_input.rb b/lib/active_interaction/grouped_input.rb
index <HASH>..<HASH> 100644
--- a/lib/active_interaction/grouped_input.rb
+++ b/lib/active_interaction/grouped_input.rb
@@ -4,5 +4,16 @@ require 'ostruct'
 
 module ActiveInteraction
   class GroupedInput < OpenStruct
+    def [](name)
+      return super if self.class.superclass.method_defined?(:[])
+
+      send(name)
+    end
+
+    def []=(name, value)
+      return super if self.class.superclass.method_defined?(:[]=)
+
+      send("#{name}=", value)
+    end
   end
 end
Define methods for backwards compatibility