def read_default_config(self):
        """Read the default config file.

        :raises DefaultConfigValidationError: There was a validation error with
                                              the *default* file.
        """
        if self.validate:
            self.default_config = ConfigObj(configspec=self.default_file,
                                            list_values=False, _inspec=True,
                                            encoding='utf8')
            valid = self.default_config.validate(Validator(), copy=True,
                                                 preserve_errors=True)
            if valid is not True:
                for name, section in valid.items():
                    if section is True:
                        continue
                    for key, value in section.items():
                        if isinstance(value, ValidateError):
                            raise DefaultConfigValidationError(
                                'section [{}], key "{}": {}'.format(
                                    name, key, value))
        elif self.default_file:
            self.default_config, _ = self.read_config_file(self.default_file)

        self.update(self.default_config)