diff --git a/@packages/imessage/Sources/IMessageSync/SyncManager.swift b/@packages/imessage/Sources/IMessageSync/SyncManager.swift
index 13df109..f19fd51 100644
--- a/@packages/imessage/Sources/IMessageSync/SyncManager.swift
+++ b/@packages/imessage/Sources/IMessageSync/SyncManager.swift
@@ -46,6 +46,14 @@ final class SyncManager: BaseSyncManager<SyncStats, SyncError> {
 
     static let syncSchemaVersion = 3
 
+    /// Overlap lookback for the incremental read. The watermark advances to the
+    /// newest synced message *date* (see `runReadCycle`), and each cycle re-reads
+    /// from `watermark − overlap` so messages that land below the watermark —
+    /// out-of-order delivery, late SMS, or a chat.db→Date timezone/DST skew — are
+    /// always re-scanned. Server upserts by external_id, so re-scanning is
+    /// idempotent (no duplicates). This is the fix for silent recent-message drop.
+    static let incrementalOverlapSeconds: TimeInterval = 2 * 60 * 60
+
     // Module-specific @Published state (base owns isSyncing/lastSyncCompletedAt/
     // currentOperation/syncError/stats).
     @Published var contactSyncInfo = ContactSyncInfo()