diff --git a/src/telegram/bot.media.test-utils.ts b/src/telegram/bot.media.test-utils.ts
index 4d49eda3f60..94084bad31c 100644
--- a/src/telegram/bot.media.test-utils.ts
+++ b/src/telegram/bot.media.test-utils.ts
@@ -1,10 +1,12 @@
-import { afterEach, beforeAll, beforeEach, expect, vi } from "vitest";
+import { afterEach, beforeAll, beforeEach, expect, vi, type Mock } from "vitest";
 import * as ssrf from "../infra/net/ssrf.js";
 import { onSpy, sendChatActionSpy } from "./bot.media.e2e-harness.js";
 
-export const cacheStickerSpy = vi.fn();
-export const getCachedStickerSpy = vi.fn();
-export const describeStickerImageSpy = vi.fn();
+type StickerSpy = Mock<(...args: unknown[]) => unknown>;
+
+export const cacheStickerSpy: StickerSpy = vi.fn();
+export const getCachedStickerSpy: StickerSpy = vi.fn();
+export const describeStickerImageSpy: StickerSpy = vi.fn();
 
 const resolvePinnedHostname = ssrf.resolvePinnedHostname;
 const lookupMock = vi.fn();