delivered the opinion of the Court.
[¶ 1] The district court dismissed this negligence action because the appellants’ notice of governmental claim did not meet constitutional requirements. We dismiss this appeal for the same reason.
ISSUES
1. Did the district court have subject matter jurisdiction over the claim?
2. Was the appellee barred by the equitable doctrine of either estoppel or laches from asserting the lack of subject matter jurisdiction?
*291FACTS
[¶2] On July 2, 1998, while staying in Alpine, Wyoming, Lisa Wilson allegedly contracted e-coli poisoning and Hemolytic-Ur-emic Syndrome by drinking water from the Town of Alpine’s (the appellee) municipal supply. On June 7, 1999, Wilson and her husband (the appellants) presented a notice of claim to the appellee pursuant to the Wyoming Governmental Claims Act, Wyo. Stat. Ann. § 1-39-101, et seq. (Lexis 1999), alleging that the appellee’s negligence had caused the appellants’ injuries. The notice of claim was signed by the appellants’ attorney, rather than by the appellants, and was not certified to under penalty of perjury. The appellee denied the claim, and the appellants filed suit on May 19, 2000. On May 28, 2004, the district court entered an order granting the appellee’s motion to dismiss, citing Beaulieu v. Florquist, 2004 WY 31, ¶ 15, 86 P.3d 863, 868-69 (Wyo.2004) and Yoak v. Ide, 2004 WY 32, ¶ 6, 86 P.3d 872, 874 (Wyo.2004), for the proposition that a governmental claim not meeting the constitutional signature and certification requirements is deficient, thereby depriving the court of subject matter jurisdiction.1 This appeal followed.
STANDARD OF REVIEW
[¶ 3] The appellee’s motion to dismiss did not identify a particular court rule as its basis, did not mention subject matter jurisdiction, and alleged solely that the notice of claim was defective. Logically, such a motion could have been made under W.R.C.P. 12(b)(6), for failure to state a claim upon which relief can be granted. The district court, however, noting that the absence of a valid notice of claim is jurisdictional, treated the motion as a motion to dismiss for lack of subject matter jurisdiction under W.R.C.P. 12(b)(1).
[¶ 4] On appeal, the appellants insist that, - because the district court considered the notice of claim, a copy of which was attached to the motion but which had not been attached to any pleading, the motion was converted to a W.R.C.P. 56 motion for summary judgment. The district court’s order does not, however, evidence such conversion, and does not contain the findings and conclusions that would suggest summary judgment.2 We are inclined to follow suit and to consider the motion as it was entitled — a motion to dismiss. In the end, it makes little difference because the material facts are not in dispute and judgment was entered as a matter of law. In reviewing both motions to dismiss and motions for summary judgment — as well as motions for judgment on the pleadings — the facts are considered in the light most favorable to the party opposing the motion, and the motion is granted only if those facts dictate that judgment should be entered as a matter of law. See Bonnie M. Quinn Revocable Trust v. SRW, Inc., 2004 WY 65, ¶ 8, 91 P.3d 146, 148 (Wyo.2004) (quoting Manion v. Chase Manhattan Mortgage Corp., 2002 WY 49, ¶ 6, 43 P.3d 576, ¶ 6 (Wyo.2002)); Rodriguez v. Casey, 2002 WY 111, ¶ 4, 50 P.3d 323, 325 (Wyo.2002) (quoting Greeves v. Rosenbaum, 965 P.2d 669, 671 (Wyo.1998)); and McLean v. Hyland Enterprises, Inc., 2001 WY 111, ¶ 6, 34 P.3d 1262, 1265 (Wyo.2001). Conclusions of law are reviewed de novo. Bixler v. Oro Management, L.L.C., 2004 WY 29, ¶ 11, 86 P.3d 843, 847 (Wyo.2004).
DISCUSSION
Subject Matter Jurisdiction
[¶ 5] The appellants presented to the appellee a notice of claim that did not *292meet the requirements of Article 16, § 7 of the Wyoming Constitution — it was neither signed by the claimants nor certified to under penalty of perjury. We will affirm the district court’s order of dismissal for lack of subject matter jurisdiction. See Wooster v. Carbon County School Dist. No. 1, 2005 WY 47, 109 P.3d 893 (Wyo.2005), and the cases cited therein. Furthermore, even if the matter was not considered jurisdictional, the notice of claim indisputably did not meet constitutional requirements and was, on its face, invalid as a governmental claim, thereby entitling the appellee to judgment as a matter of law. Id. And finally, the district court appropriately dismissed with prejudice, inasmuch as it was then impossible for the appellants to comply with the mandatory filing deadline of Wyo. Stat. Ann. § 1-39-113, which is a substantive non-claim statute, rather than a procedural statute of limitations. Bell v. Schell, 2004 WY 153, ¶¶ 25-36, 101 P.3d 465, 472-76 (Wyo.2004).
Equity
[¶ 6] Because the record on appeal is so sparse, we have no way of knowing whether the appellants’ estoppel and laches arguments were raised below and, if so, how they were treated by the district court. We suspect, given the jurisdictional dismissal, that they were not considered by that court. In this Court, the appellants’ equitable arguments are supported largely by reference to their attorney’s affidavit setting forth the amount of time and money spent on the litigation. This affidavit may or may not have been considered by the district court, and it played no part in its decision. Because we agree with the jurisdictional dismissal, we will not further consider the equitable arguments.
CONCLUSION
[¶ 7] The complaint in this action is based upon an invalid governmental claim. That fact deprived the district court of jurisdiction to consider the matter on the merits. Because we can have no better jurisdiction than did the district court, we dismiss this appeal. Lankford v. City of Laramie, 2004 WY 143, ¶ 23, 100 P.3d 1238, 1244 (Wyo.2004).
BURKE, Justice, filed a dissenting opinion, with which KITE, Justice, joined.
. Article 16, § 7 of the Wyoming Constitution provides as follows:
No money shall be paid out of the state treasury except upon appropriation by law and on warrant drawn by the proper officer, and no bills, claims, accounts or demands against the state, or any county or political subdivision, shall be audited, allowed or paid until a full itemized statement in writing, certified to under penalty of perjury, shall be filed with the officer or officers whose duty it may be to audit the same.
(Emphasis added.)
. None of the following were included in the record on appeal, leaving a considerable gap in this Court’s ability to understand what happened below: the appellants' traverse to the motion to dismiss, the appellee’s response to that traverse, and the hearing transcript. We do not know, for instance, whether the district court considered the affidavit of the appellants' counsel.