diff --git a/src/services/mcp/utils/__tests__/oauth.spec.ts b/src/services/mcp/utils/__tests__/oauth.spec.ts
index e2242c8ef8..b276f60fd4 100644
--- a/src/services/mcp/utils/__tests__/oauth.spec.ts
+++ b/src/services/mcp/utils/__tests__/oauth.spec.ts
@@ -1,4 +1,4 @@
-import { describe, it, expect, vi, beforeEach } from "vitest"
+import { describe, it, expect, vi, beforeEach, afterAll } from "vitest"
 
 // Mock the SDK's discoverOAuthProtectedResourceMetadata
 vi.mock("@modelcontextprotocol/sdk/client/auth.js", () => ({
@@ -9,6 +9,7 @@ import { discoverOAuthProtectedResourceMetadata } from "@modelcontextprotocol/sd
 import { fetchOAuthAuthServerMetadata } from "../oauth"
 
 const mockFetch = vi.fn()
+const originalFetch = global.fetch
 global.fetch = mockFetch
 
 describe("fetchOAuthAuthServerMetadata", () => {
@@ -16,6 +17,10 @@ describe("fetchOAuthAuthServerMetadata", () => {
 		vi.clearAllMocks()
 	})
 
+	afterAll(() => {
+		global.fetch = originalFetch
+	})
+
 	it("returns null when resource metadata has no authorization_servers", async () => {
 		;(discoverOAuthProtectedResourceMetadata as any).mockResolvedValue({
 			resource: "https://example.com/",