Father appeals from a judgment awarding custody of the parties’ minor child to mother. We affirm.

The dispute concerns the custody of a child born July 6,1987. Mother and father never married.1 Paternity was not disputed and, in August 1987, an administrative order establishing paternity was entered in circuit court.2 Mother had physical custody of the child. Father visited the child regularly until a few weeks after her birth. At that time, a dispute arose between the parties, and father threatened mother.3 Mother then moved with the child from her family’s home and concealed the location from father. In October 1987, father obtained an order specifying visitation rights, which mother did not obey.4 Father then initiated proceedings relating to mother’s failure to obey the visitation order but was unable to serve mother. Finally, in October 1988, father filed motions to change custody of the child, terminate his child support and hold mother in contempt. He also moved for an order permitting alternative service5 on mother. Alternative service was ordered on October 10, and that service was completed December 9. On December 23, the court *338entered an order changing the child’s custody to father and terminating support after finding mother in default for failure to appear. The court also issued a writ of assistance to Oregon law enforcement officials ordering them to place the child, if found, in father’s custody. No judgment was ever entered. At some point, mother moved with the child to California and went into hiding using an assumed name. She lived there for about four years until she was discovered by the police and father. She returned to Oregon in October 1992 and, in February 1993, pled guilty to custodial interference in the second degree. The juvenile court granted temporary custody of the child to Children’s Services Division.6 However, mother retained physical custody subject to visitation by father.

In February 1993, mother moved to dismiss the 1988 order granting father custody on the grounds that service on her had been inadequate.7 She also moved to modify the 1988 order to return legal custody of the child to her.

After an evidentiary hearing, the trial court held that the service was inadequate and set aside the 1988 custody order.8 It then found that, although both parents were *339fit, it was in the best interests of the child to grant mother custody. In the alternative, the court found that even if service of the 1988 order had been adequate, mother was still entitled to custody because she had shown a change in circumstances.

Father’s first assignment of error is that the trial court erred in setting aside the prior custody order on the ground that service on mother was inadequate. His second assignment is that the trial court erred in granting custody to mother. The issue of adequate service is important because if the order awarding custody to father is set aside, then the present action is the first time that a court has determined custody and mother need only show that granting custody to her is in the best interests of the child. ORS 109.175.9 If the order is not set aside, then mother must seek to modify it. Father argues that to modify the order, mother must show that a substantial change in circumstances has occurred since entry of the order before the issue of the child’s best interests can be reached. We begin with father’s first assignment.

We generally review a trial court’s decision to set aside a judgment or default order for abuse of discretion. Weaver and Weaver, 119 Or App 478, 481, 851 P2d 629 (1993). However, that discretion is controlled by fixed legal principles. Hiatt v. Congoleum Industries, 279 Or 569, 575, 569 P2d 567 (1977). Because adequacy of service is a question of law, Luyet v. Ehrnfelt, 118 Or App 635, 637-38, 848 P2d 654 (1993), we review it for legal error. ORAP 5.45 n 1.

*340Father argues that the trial court, in setting aside the order of default, erroneously disregarded the adequacy of the alternative service under ORCP 7 D(6)(a). We agree.

The 1988 order authorizing alternative service was based on father’s affidavit, which alleged that: mother had avoided service; mother lived at her parents’ address;10 mother received her mail at her parents’ address; mother’s public assistance checks were mailed to that address; and mother, mother’s father, and mother’s mother all provided that address to the Department of Motor Vehicles. The order required personal service on mother’s father, mother’s mother, and the Oregon Department of Human Resources (DHR). It also required father to notify mother by certified mail, in care of her father. Service on DHR was made by delivery to the Attorney General’s office on October 13. Mother’s mother was personally served at the parents’ address on November 26. Mother’s father was personally served at his place of work on December 6. Father attempted to serve mother by certified mail on December 9, but her parents returned it unopened. At some point, mother was aware of father’s efforts to serve her through her parents and left the state to avoid service.11 The parties disagree on whether mother received actual notice.

In seeking to set aside the prior order of custody, mother argued that father had not effected adequate substitute service under ORCP 7 D(2)(b). She did not, however, *341argue that the 1988 order authorizing alternative service was deficient or that father somehow failed to comply with the requirements of that order. The trial court found that father had not complied with the substitute service provisions of ORCP 7 D(2)(b) but did not identify any deficiency in father’s compliance with the order authorizing alternative service. Because father’s alternative service of the 1988 motion to change custody was legally sufficient, the trial court erred in setting aside the 1988 default order of custody.12

Because the 1988 order granting father custody is valid, we turn to the issue of the child’s custody. We review de novo. ORS 19.125(3).

A party seeking to modify a previous custody order must show that there has been a substantial change of circumstances since the previous order was entered. Greisamer and Greisamer, 276 Or 397, 400, 555 P2d 28 (1976). The parties disagree on whether the change in circumstances rule applies to an order taken by default. If it does, they also disagree on whether mother has shown that a substantial change of circumstances occurred. We first address the issue of whether the change of circumstances rule applies.

Father argues that mother must show a substantial change of circumstances under Welby and Welby, 89 Or App 412, 749 P2d 602 (1988). In Welby, the parties had initially agreed that the father should have custody. Neither party appeared in court and that agreement was incorporated into the judgment of dissolution. Instead of giving the child to the father, the mother absconded with the child and kept their whereabouts secret for two years. In Welby, the trial court held that, because the custody issue had never been litigated, a change of circumstances was not required. We disagreed.

Here, the trial court attempted to distinguish Welby as follows:

*342“In my view, however, Welby is distinguishable. First of all in Welby the parties arrived at a custody decree by stipulation. Thus the law presumes that the decision was in the best interest of the child and that those best interests, and the maintenance of the stability of that best interest situation, can only be overcome by a showing of substantial change in circumstance. Here, however, the earlier decree was by default — a default this court has just decided was improperly granted and has been set aside. Thus there has been no determination in this case either by stipulation or by the court that custody with one parent is in the child’s best interest.”

Mother basically echos the trial court’s position and argues that we should likewise find that Welby is distinguishable from the circumstances here. Alternatively, mother asks us to overrule Welby. We decline to do either.

The fact that this case involves a custody order taken by default does not relieve mother of her burden to show a change of circumstances. The change of circumstances rule applies even if the prior order was entered ex parte. Henrickson v. Henrickson, 225 Or 398, 402, 358 P2d 507 (1961).

Mother argues that, in the case of a default order, there is no starting point from which to determine a change of circumstances. To the extent that is a problem, it can be remedied. During the modification proceeding, the parties may introduce evidence to show what the circumstances were at the time the previous order was entered. Stevens and Stevens, 107 Or App 137, 140, 810 P2d 1334, rev den 312 Or 81 (1991). That will establish the starting point to determine whether a change of circumstances has occurred.

We also find no basis on which to overrule Welby. The change of circumstances rule is required by a long line of precedent, which we cannot disregard. See, e.g., Greisamer, 276 Or at 400. Mother’s argument that the change of circumstances rule lacks statutory authority ignores ORS 109.175,13 which applies in this case. That statute provides that “[t]he first time the court determines” custody in a paternity matter, “neither parent shall have the burden of proving a change of circumstances.” That wording strongly implies that *343when a proceeding involves a modification rather than an initial determination, a change of circumstances is required.

Because we conclude that the change of circumstances rule applies, we must now determine whether mother met her burden. Father argues that, under Welby, the trial court erred by treating the child’s “strengthened relationship” with mother as evidence of a change of circumstances. In Welby, we held:

“Mother cannot rely on evidence of her strengthened relationship with her child which resulted from her felonious abduction and secreting of him to show a substantial change of circumstances. So to hold would encourage custodial interference such as occurred here to obtain an advantage in custody disputes.” 89 Or App at 414.

Our language in Welby should not be read as broadly as father does here. Welby does not stand for the proposition that a “strengthened relationship” with the abducting parent can never be used as evidence of a change of circumstances. In Welby, the mother relied on a “strengthened relationship” that was solely the result of the child’s abduction. However, even where a child has been abducted or secreted, there may be other unrelated circumstances that may be the basis of a “strengthened relationship” with the abducting parent. In other words, if the “strengthened relationship” is due to circumstances not solely related to the child’s abduction or secreting, it may be considered by the court in determining whether there has been a change of circumstances.

Here, the trial court found that mother had proved a change of circumstances “based on the child’s unfamiliarity with [father] and the risk now posed to the emotional stability of the child if [her] custody were awarded to [father].” Father argues that the child’s unfamiliarity with father is simply the flip-side of the “strengthened relationship” argument and, as such, mother cannot use that unfamiliarity as evidence of a change of circumstances. We agree that using the child’s unfamiliarity with father as evidence of a change of circumstances is really no different from using the child’s “strengthened relationship” with mother. However, we do not agree with father’s argument that that is what the trial court did in finding a substantial change of circumstances.

*344After mother returned to Oregon and submitted to the jurisdiction of the court, a visitation schedule with father was established immediately. Within two weeks of father’s introduction to the child, he was granted physical custody on alternating weeks. A few days into the first week of father’s custody, the parties agreed that the child could not last the entire week with father. The parties then agreed to alternate custody every two days. Eventually, four-and-one-half months after the juvenile court’s initial visitation order, mother and father again alternated custody on a weekly basis. According to the child’s therapist, the manner in which father was abruptly interjected into the child’s life has had a severely detrimental impact on the child emotionally, which will only be exacerbated if father were to be awarded sole custody of the child.

The emotional problems experienced by the child, caused by the manner in which father was abruptly interjected into the child’s life, and the resulting risk of further harm to the child if father were to have sole custody are circumstances not solely the result of mother’s abduction and secreting of the child. The trial court’s conclusion that those post-abduction events resulted in a substantial change of circumstances was not error.

The only remaining issue is whether awarding custody to mother is in the child’s best interests. Father does not dispute the trial court’s determination that it is in the child’s best interests to grant mother custody. We conclude that the trial court properly awarded custody to mother.

Affirmed.

concurring.

I join in the lead opinion’s disposition and in its reasoning. I write separately to comment on one aspect of the case. I agree, for the reasons stated in the lead opinion, 140 Or App at 342, that the circumstances of this case are distinguishable from those in Welby and Welby, 89 Or App 412, 414, 749 P2d 602 (1988), where we held that the “strengthened relationship” between a parent and child that results *345from custodial interference or similar wrongful conduct cannot be the basis for finding a substantial change of circumstances. Here, as the lead opinion holds, the changes in circumstances did not result solely from the custodial interference, and Welby therefore does not control.

In my view, however, Welby is due for a comprehensive reexamination. Welby’s blanket rule has two interrelated defects, both of which were identified by Judge Rossman in his dissent in that case: First, it eliminates the factual inquiries that are truly relevant to a custody determination and replaces them with a rule of deterrence that is more suitably addressed — and has been addressed — by the criminal law; and, second, it visits the sins of the absconding parent on the head of the abducted child.

No one condones custodial interference. I do not suggest that “bonding” that results from that act should necessarily or generally be given the same weight in determining whether circumstances have.changed as the affection and dependence that evolve from lawful contacts between the noncustodial parent and the child. That does not mean, however, that a child who has been abducted should be deprived of all consideration of the emotional ties that he or she has developed, and which all other children are entitled to have considered in custody decisions. Stated another way, the fact of the illegal conduct should be considered in making the change of circumstances and custodial determinations, but it should not be treated as a universal and per se negative answer to the inquiry, as Welby would require.

To illustrate, there would normally be a vast difference in both the bonding and the change of circumstances analysis if a child became primarily affiliated with a parent at the age of two and had remained so for 10 years, rather than if the affiliation began at age six and had endured for one year. Under Welby, however, that and similarly graphic factors would have to be disregarded if the primary affiliation began by reason of custodial interference; in such instances, under Welby, a clear and substantial change of circumstances, as well as the best interests of the child, could be given no consideration if they happened to originate with an abduction, however remote its occurrence.

*346Welby cites no authority for its underlying proposition that the deterrence of a particular kind of parental misconduct is not only to take precedence over, but is to replace the usual mode of analysis in change of custody cases. It may be that the resolution under Welby and under the conventional criteria will generally coincide. However, beyond the fact that Welby replaces the child’s well-being with the parent’s punishment or deterrence as the exclusive determinant, its principal operational vice may inhere in its inflexibility: It is simply not correct to say that the relationship of a child with both of its parents cannot be changed beyond the possibility of meaningful restoration by the passage of time, simply because the time period began with a wrongful act.