delivered the opinion of the court:
On August 12, 1985, plaintiffs T. L. Cain, Wayne T. Cain, and Edward J. Cain, as coexecutors of the estate of Marie M. Cain, filed a medical malpractice action in the circuit court of Champaign County against defendant Fred Sukkar, and naming Cole Hospital, Inc., A. Barnes, Americana Healthcare Center, Kenneth L. Bussey, M.D., and Anthony F. Karich, M.D., as respondents in discovery (Ill. Rev. Stat. 1985, ch. 110, par. 2 — 402).
On January 9, 1986, Sukkar filed a motion for summary judgment on the count filed against him in the complaint. (Ill. Rev. Stat. 1985, ch. 110, par. 2 — 1005.) On February 3, 1986, plaintiffs filed the affidavit of purported expert, Dr. Richard C. Gardner, in opposition to Sukkar’s motion for summary judgment. Thereafter, Sukkar moved to strike Gardner’s affidavit.
On February 5, 1986, plaintiffs filed an objection to Sukkar’s motion to strike the affidavit, a motion to consolidate the instant action with one naming Americana Healthcare Center as defendant (Ill. Rev. Stat. 1985, ch. 110, par. 2 — 1006), a motion to add Kenneth L. Bussey, M.D., as a party defendant, and a first amendment to their original complaint alleging medical malpractice and naming Bussey as a defendant. On March 17, 1986, respondents in discovery, Cole Hospital, Inc., A. Barnes, and Anthony F. Karich, M.D., were dismissed with prejudice on the plaintiffs’ motion.
On May 16, 1986, Sukkar filed a motion to strike Dr. Gardner’s affidavit as being merely conclusory and failing to comply with Supreme Court Rule 191 (107 Ill. 2d R. 191). A hearing on Sukkar’s motions for summary judgment and to strike Gardner’s affidavit was held on July 3, 1986. At the conclusion of the hearing, Gardner’s affidavit was stricken for failure to comply with the requirements of Supreme Court Rule 191 and Sukkar’s motion for summary judgment was taken under advisement.
On July 10, 1986, the trial court entered its "written order finding, based upon the uncontradicted affidavit of the defendant, that there was no genuine issue of material fact as to the action against Sukkar. Thus, the court entered summary judgment in favor of Sukkar and against the plaintiffs. Further, the court entered its finding of no just reason to delay enforcement or appeal. 107 Ill. 2d R. 304(a).
*944On July 29, 1986, the plaintiffs filed a motion for reconsideration and to vacate summary judgment in favor of Sukkar. (Ill. Rev. Stat. 1985, ch. 110, par. 2 — 1203.) On September 8, 1986, Sukkar filed a motion to strike plaintiffs’ motion for reconsideration, arguing that the trial court had no jurisdiction to hear the motion. A hearing was held on September 29, 1986, after which the trial court denied Sukkar’s motion to strike and took plaintiffs’ motion for reconsideration under advisement.
On October 7, 1986, the trial court entered its “Memorandum Upon Vacating Summary Judgment for Defendant Sukkar.” The court found that Gardner’s affidavit was erroneously stricken and plaintiffs were granted leave to refile the affidavit. Further, the court found that a genuine issue of material fact was raised thereby. Thus, the court vacated its July 10, 1986, order granting summary judgment in favor of Sukkar and in turn denied Sukkar’s motion for summary judgment. Sukkar now appeals from this order.
Sukkar contends on appeal that as a consequence of the trial court’s entry of a Rule 304(a) finding, which immediately followed the entry of summary judgment in favor of Sukkar, the summary judgment was final and appealable and the trial court was divested of jurisdiction. Sukkar points out that the court on July 9, 1986, entered summary judgment in his favor and thereafter entered a finding pursuant to Supreme Court Rule 304(a) of no just reason to delay enforcement or appeal. Sukkar further points out that within the 30-day period following the entry of the Rule 304(a) finding, the plaintiffs filed a motion to reconsider or vacate the order granting summary judgment, which was ultimately allowed on October 7, 1986. Sukkar contends that as a result of the Rule 304(a) finding, the order granting summary judgment became immediately appealable and the circuit court was divested of jurisdiction to entertain a petition to reconsider or vacate the order.
Initially, we note that a trial court’s order vacating a judgment is ordinarily not appealable because it leaves the merits of the case pending and, therefore, is not a final order. (William Aupperle & Sons, Inc. v. American National Bank & Trust Co. (1975), 28 Ill. App. 3d 573, 329 N.E.2d 458.) However, Sukkar contends the circuit court lacked jurisdiction on October 7, 1986, to vacate the summary judgment in his favor. If Sukkar is correct, the order vacating the judgment in his favor would be void and could be challenged in this court because a void order can be directly attacked at any time on appeal. (Petersen Brothers Plastics, Inc. v. Ullo (1978), 57 Ill. App. 3d 625, 373 N.E.2d 416.) Hence, we must decide whether the circuit *945court’s entry of the 304(a) finding divested the court of jurisdiction.
It is fundamental that the proper filing of a notice of appeal causes the jurisdiction of the appellate court to attach instanter and deprives the trial court of jurisdiction to modify its judgment or to rule on matters of substance which are the subject of appeal. (Montgomery Ward & Co. v. Wetzel (1981), 98 Ill. App. 3d 243, 423 N.E.2d 1170.) Once an appeal has been duly filed in the appellate court by filing a notice of appeal, the trial court is restrained from entering any order which would change or modify the judgment or its scope, and from entering any order which would have the effect of interfering with the review of the judgment. (Bachewicz v. American National Bank & Trust Co. (1985), 135 Ill. App. 3d 294, 482 N.E.2d 95 (and cases cited therein).) In the case at bar, however, no notice of appeal was filed which would have deprived the circuit court of jurisdiction to rule on the plaintiffs’ motion to reconsider or vacate the summary judgment.
Rule 304, which governs “appeals from Final Judgments That Do Not Dispose of an Entire Proceeding,” provides in pertinent part:
“If multiple parties or multiple claims for relief are involved in an action, an appeal may be taken from a final judgment as to one or more but fewer than all of the parties or claims only if the trial court has made an express written finding that there is no just reason for delaying enforcement or appeal. Such a finding may be made at the time of the entry of the judgment or thereafter on the court’s own motion or on motion of any party. The time for filing the notice of appeal shall run from the entry of the required finding.” (Emphasis added.) (107 Ill. 2d R. 304.)
Although Rule 304 does not include any provision for post-judgment motions, our supreme court and several appellate courts have discussed situations in which post-judgment motions have followed the entry of findings of appealability pursuant of Rule 304(a). None of these courts were called upon to address the precise issue before this court. Nevertheless, the opinions demonstrate that following the entry of a Rule 304(a) finding, the circuit court retains jurisdiction to rule on a timely post-trial motion and the circuit court is not divested of jurisdiction until such time as a notice of appeal is timely filed. (See, e.g., Elg v. Whittington (1987), 119 Ill. 2d 344; Mau v. Unarco Industries, Inc. (1985), 135 Ill. App. 3d 736, 481 N.E.2d 1207; In re Estate of Tingos (1979), 72 Ill. App. 3d 703, 390 N.E.2d 1349; Petersen Brothers Plastics, Inc. v. Ullo (1978), 57 Ill. App. 3d 625, *946373 N.E.2d 416.) In light of the foregoing, we hold that the circuit court had jurisdiction to rule on the plaintiffs’ timely motion to reconsider or vacate the summary judgment in favor of Sukkar.
In so holding we point out that pursuant to Rule 304(a) the time for filing the notice 'of appeal shall run from the entry of the required finding. Our supreme court in Elg has recently determined that the filing of a timely motion to reconsider a piecemeal judgment will not toll the running of the 30-day period for filing a timely notice of appeal from that judgment based upon a Rule 304(a) finding. The Elg court recognized that Rule 304(a) places the piecemeal appellant in a somewhat worse position than the usual appellant, who need not file a notice of appeal until 30 days after the denial of a motion attacking the original judgment. The court reasoned, however, that this difference in treatment is justified by the fact that a Rule 304(a) appeal is an exception to the general policy disfavoring piecemeal appeals. (Elg, 119 Ill. 2d 344.) Further, the court stated that a new rule or decision will be given prospective operation whenever injustice or hardship due to justifiable reliance on the overruled decision would thereby be averted. (Elg, 119 Ill. 2d 344.) Thus, the court held that its decision in Elg applied prospectively to all cases in which the notice of appeal was filed or due to be filed on or after November 16, 1987. (Elg, 119 Ill. 2d 344.) In reaching its decision the court stated:
“Consideration of the purpose of our holding and the balance of the equities favors a prospective application. The purpose of our holding is to insure that parties contesting piecemeal judgments swiftly prosecute their appeals without engaging in unnecessary delay. In all cases previously decided or now pending the delay caused by the filing of post-trial motions has already taken place. Prospective application will not, therefore, thwart the purpose of the rule. Moreover, retroactive application of the rule would provide appellees who benefit from possibly erroneous piecemeal judgments with the unearned windfall of the dismissal of appeals against them. Conversely, it would unfairly deprive many appellants of an opportunity to have meritorious appeals heard. We believe that these considerations outweigh any prejudice caused to appellees by the unnecessary delay of these appeals.” (Elg, 119 Ill. 2d at 359.)
Hence, Elg does not apply to the instant case. Accordingly, the trial court had authority to enter its order of October 7, 1986, vacating the previous summary judgment entered in favor of Sukkar on July 10, 1986. The order of the trial court entered October 7, 1986, under *947these circumstances is not a final order and thus is not appealable as an interlocutory order.
For the foregoing reason, the appeal is dismissed.
Appeal dismissed.
McCullough, j., concurs.