diff --git a/mobile/ios/BuzzPushKit/Sources/BuzzPushKit/BuzzNotificationCache.swift b/mobile/ios/BuzzPushKit/Sources/BuzzPushKit/BuzzNotificationCache.swift
index 33ca6a9484..d4bf33c70d 100644
--- a/mobile/ios/BuzzPushKit/Sources/BuzzPushKit/BuzzNotificationCache.swift
+++ b/mobile/ios/BuzzPushKit/Sources/BuzzPushKit/BuzzNotificationCache.swift
@@ -102,6 +102,14 @@ public final class BuzzNotificationCache: @unchecked Sendable {
   /// message can carry an earlier time than one already shown. Anything older is
   /// history, not the message a push is for.
   public static let presentationReorderWindow = 15 * 60
+
+  /// The oldest time still within ``presentationReorderWindow`` of `newest`. Saturates,
+  /// because a signed event can carry any `created_at` and an overflow would crash the
+  /// extension on every push.
+  static func presentationCutoff(after newest: Int) -> Int {
+    let (cutoff, overflow) = newest.subtractingReportingOverflow(presentationReorderWindow)
+    return overflow ? .min : cutoff
+  }
   /// Retention keeps up to this many entries by `watermark` and as many by `createdAt`,
   /// so neither future-dated entries nor a burst of recent ones can evict the other.
   static let maximumPresentedMessages = 256
@@ -309,7 +317,7 @@ public final class BuzzNotificationCache: @unchecked Sendable {
           return index
         case .success(let entries):
           guard !entries.contains(where: { $0.id == candidate.event.id }) else { continue }
-          if let newestShown, watermark < newestShown - Self.presentationReorderWindow {
+          if let newestShown, watermark < Self.presentationCutoff(after: newestShown) {
             continue
           }
         }
@@ -409,7 +417,7 @@ public final class BuzzNotificationCache: @unchecked Sendable {
       if let presented = state.presented, let newest = presented.map(\.watermark).max() {
         // The age check rejects anything older than the window, so those entries can
         // go. A future-dated entry stays while the relay may still rank it first.
-        let cutoff = newest - Self.presentationReorderWindow
+        let cutoff = Self.presentationCutoff(after: newest)
         // Entries are newest claim first, so ties keep the most recent claims.
         let current = Array(presented.filter { $0.createdAt >= cutoff }.enumerated())
         func newestIDs(by key: (PresentedMessage) -> Int) -> [String] {
diff --git a/mobile/ios/BuzzPushKit/Tests/BuzzPushKitTests/BuzzPushNotificationResolverTests.swift b/mobile/ios/BuzzPushKit/Tests/BuzzPushKitTests/BuzzPushNotificationResolverTests.swift
index 2e0555d843..d04cd15380 100644
--- a/mobile/ios/BuzzPushKit/Tests/BuzzPushKitTests/BuzzPushNotificationResolverTests.swift
+++ b/mobile/ios/BuzzPushKit/Tests/BuzzPushKitTests/BuzzPushNotificationResolverTests.swift
@@ -513,6 +513,29 @@ final class BuzzPushNotificationResolverTests: XCTestCase {
     XCTAssertNil(push(), "a future-dated message is not shown again")
   }
 
+  func testExtremeTimestampsDoNotCrashTheClaim() throws {
+    let root = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+    addTeardownBlock { try? FileManager.default.removeItem(at: root) }
+    let scope = try XCTUnwrap(BuzzNotificationCacheScope(community: community()))
+    let cache = BuzzNotificationCache(
+      directory: root, now: { Date(timeIntervalSince1970: TimeInterval(Self.now)) },
+      isCurrent: { $0 == scope })
+    func claim(_ event: VerifiedNostrEvent) throws -> Bool {
+      try cache.claimFirstUnpresented([(event: event, scope: scope)], scopes: [scope]) == 0
+    }
+    func message(_ content: String, createdAt: Int) throws -> VerifiedNostrEvent {
+      try Self.signedEvent(privateKey: Self.profilePrivateKey, createdAt: createdAt,
+        kind: 9, tags: [["h", Self.channelID]], content: content)
+    }
+    let ancient = try message("Ancient", createdAt: Int.min)
+    XCTAssertTrue(try claim(ancient))
+    XCTAssertFalse(try claim(ancient))
+    XCTAssertTrue(try claim(try message("Current", createdAt: Self.now)))
+    XCTAssertFalse(try claim(try message("Also ancient", createdAt: Int.min + 1)),
+      "a message far older than one already shown is history")
+    XCTAssertTrue(try claim(try message("Far future", createdAt: Int.max)))
+  }
+
   func testFutureDatedEntriesDoNotEvictAClaimedMessage() throws {
     let root = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
     addTeardownBlock { try? FileManager.default.removeItem(at: root) }