Base#[] and Base#[]= are aliases so implement them as aliases :)

activerecord/lib/active_record/base.rb

@@ -1460,19 +1460,6 @@ def attribute_names
         @attributes.keys
       end
 
-      # Returns the value of the attribute identified by <tt>attr_name</tt> after it has been typecast (for example,
-      # "2004-12-12" in a data column is cast to a date object, like Date.new(2004, 12, 12)).
-      # (Alias for the protected read_attribute method).
-      def [](attr_name)
-        read_attribute(attr_name)
-      end
-
-      # Updates the attribute identified by <tt>attr_name</tt> with the specified +value+.
-      # (Alias for the protected write_attribute method).
-      def []=(attr_name, value)
-        write_attribute(attr_name, value)
-      end
-
       # Allows you to set all the attributes at once by passing in a hash with keys
       # matching the attribute names (which again matches the column names).
       #
@@ -1873,6 +1860,17 @@ def clear_timestamp_attributes
     include Aggregations, Transactions, Reflection, Serialization
 
     NilClass.add_whiner(self) if NilClass.respond_to?(:add_whiner)
+
+    # Returns the value of the attribute identified by <tt>attr_name</tt> after it has been typecast (for example,
+    # "2004-12-12" in a data column is cast to a date object, like Date.new(2004, 12, 12)).
+    # (Alias for the protected read_attribute method).
+    alias [] read_attribute
+
+    # Updates the attribute identified by <tt>attr_name</tt> with the specified +value+.
+    # (Alias for the protected write_attribute method).
+    alias []= write_attribute
+
+    public :[], :[]=
   end
 end