diff --git a/src/services/adminPointService.ts b/src/services/adminPointService.ts
index ea5084f..fb4b06d 100644
--- a/src/services/adminPointService.ts
+++ b/src/services/adminPointService.ts
@@ -2,4 +2,4 @@ import { firestore } from "../firebase";
 import { HttpError } from "../middleware/errors";
 import { PointLedgerType } from "../types/points";
 import { applyPointChangesTx } from "./pointService";
-export async function adminPointChange(uid: string, amount: number, kind: "credit" | "debit", clientIdempotencyKey: string, reason: string, actor: string, reversalOf?: string) { if (!/^[A-Za-z0-9_-]{1,100}$/.test(clientIdempotencyKey) || !Number.isSafeInteger(amount) || amount <= 0 || typeof reason !== "string" || reason.length < 1 || reason.length > 500) throw new HttpError(400, "invalid admin point change", "INVALID_INPUT"); return firestore.runTransaction((tx) => applyPointChangesTx(tx, uid, [{ txId: `${uid}:admin:${clientIdempotencyKey}`, type: kind === "credit" ? PointLedgerType.AdminCredit : PointLedgerType.AdminDebit, amount, adminReason: reason, adminActor: actor, reversalOf }])); }
+export async function adminPointChange(uid: string, amount: number, kind: "credit" | "debit", clientIdempotencyKey: string, reason: string, actor: string, reversalOf?: string) { if (!/^[A-Za-z0-9_-]{1,100}$/.test(clientIdempotencyKey) || !Number.isSafeInteger(amount) || amount <= 0 || typeof reason !== "string" || reason.length < 1 || reason.length > 500) throw new HttpError(400, "invalid admin point change", "INVALID_INPUT"); return firestore.runTransaction((tx) => applyPointChangesTx(tx, uid, [{ txId: `${uid}:admin:${clientIdempotencyKey}`, type: kind === "credit" ? PointLedgerType.AdminCredit : PointLedgerType.AdminDebit, amount, adminReason: reason, adminActor: actor, ...(reversalOf !== undefined ? { reversalOf } : {}) }])); }
diff --git a/tests/services/adminPointService.test.ts b/tests/services/adminPointService.test.ts
new file mode 100644
index 0000000..e5b5e6d
--- /dev/null
+++ b/tests/services/adminPointService.test.ts
@@ -0,0 +1,28 @@
+import { describe, expect, it } from "vitest";
+import { firestore } from "../../src/firebase";
+import { adminPointChange } from "../../src/services/adminPointService";
+
+const uid = "admin-point-service-test-user";
+
+describe("adminPointChange", () => {
+  it("reversalOf 없이 지급해도 원장 문서에 undefined 키가 들어가지 않는다", async () => {
+    // 어드민 웹의 일반 지급은 reversalOf 를 보내지 않는다 — undefined 가 Firestore 까지
+    // 흘러가면 "Cannot use undefined as a Firestore value" 로 지급 전체가 실패한다.
+    const key = `no-reversal-${Date.now()}`;
+    const wallet = await adminPointChange(uid, 100, "credit", key, "테스트 지급", "admin-uid");
+
+    expect(wallet?.availableBalance).toBeGreaterThanOrEqual(100);
+    const entry = await firestore.doc(`users/${uid}/pointLedger/${uid}:admin:${key}`).get();
+    expect(entry.exists).toBe(true);
+    expect(entry.data()).not.toHaveProperty("reversalOf");
+    expect(entry.data()).toMatchObject({ adminReason: "테스트 지급", adminActor: "admin-uid", amount: 100 });
+  });
+
+  it("reversalOf 를 명시하면 원장에 그대로 기록된다", async () => {
+    const key = `with-reversal-${Date.now()}`;
+    await adminPointChange(uid, 50, "credit", key, "정정 지급", "admin-uid", "prev-tx-id");
+
+    const entry = await firestore.doc(`users/${uid}/pointLedger/${uid}:admin:${key}`).get();
+    expect(entry.data()).toMatchObject({ reversalOf: "prev-tx-id" });
+  });
+});