def _decrement_version(lambda_config):
    """Decrement the Lambda version, if possible.

    Args:
        lambda_config (dict): Lambda function config with 'current_version'

    Returns:
        True if the version was changed, False otherwise
    """
    current_version = lambda_config['current_version']
    if current_version == '$LATEST':
        return False

    int_version = int(current_version)
    if int_version <= 1:
        return False

    lambda_config['current_version'] = int_version - 1
    return True