Returning null in a method that accounts for multiple conditions

Consider the following method:

private static String method (String string) {
    if (string.equals("conditionOne")) {
        return value;
    } else if (string.equals("conditionTwo")) {
        return symbol;
    } else {
        return null;
    }
}

Let's say I am checking for two conditions, conditionOne and conditionTwo. Also, assume that some other part of the program ensures that only these two cases will ever happen. Since the method has to return something for all cases to avoid a compiler error, is it okay to return null for the final else block just for syntactical purposes since that part will never execute?

Thanks