diff --git a/test/google.service.spec.ts b/test/google.service.spec.ts
index e5c6203..1f89b63 100644
--- a/test/google.service.spec.ts
+++ b/test/google.service.spec.ts
@@ -14,6 +14,7 @@ describe("GoogleService", () => {
       driveMirrorSpreadsheetUrl: "https://docs.google.com/spreadsheets/d/sheet_123",
       driveMirrorLastSyncedAt: new Date("2026-01-02T00:00:00.000Z"),
       lastSyncedAt: new Date("2026-01-02T00:00:00.000Z"),
+      dataSystemMode: "google_sheets_mirror",
       isConnected: true,
     });
     const service = new GoogleService(prisma as any);
@@ -30,6 +31,12 @@ describe("GoogleService", () => {
         lastSyncedAt: new Date("2026-01-02T00:00:00.000Z"),
         ownership: "user_google_drive",
       },
+      dataSystem: {
+        mode: "google_sheets_mirror",
+        operationalSystemOfRecord: "ledgerone_backend_db",
+        userOwnedMirror: true,
+        note: "LedgerOne writes a best-effort user-owned Google Sheets mirror while the application database remains the operational store.",
+      },
     });
   });
 });