def construct_joins(custom_joins = nil)          
    polymorphic_join = nil
    if @reflection.through_reflection.options[:as] || @reflection.source_reflection.macro == :belongs_to
      reflection_primary_key = @reflection.klass.primary_key
      source_primary_key     = @reflection.source_reflection.primary_key_name
    else
      reflection_primary_key = @reflection.source_reflection.primary_key_name
      # I think that it is using the wrong key
      # There is to way to override this broken behavior because there is no support for foreign_key as an option
      # Add in the check for foreign key. This makes the behavior match the :include behavior for the same association
      source_primary_key     = @reflection.options[:foreign_key] || @reflection.klass.primary_key
      if @reflection.source_reflection.options[:as]
        polymorphic_join = "AND %s.%s = %s" % [
          @reflection.table_name, "#{@reflection.source_reflection.options[:as]}_type",
          @owner.class.quote(@reflection.through_reflection.klass.name)
        ]
      end
    end

    "INNER JOIN %s ON %s.%s = %s.%s %s #{@reflection.options[:joins]} #{custom_joins}" % [
      @reflection.through_reflection.table_name,
      @reflection.table_name, reflection_primary_key,
      @reflection.through_reflection.table_name, source_primary_key,
      polymorphic_join
    ]
  end