diff --git a/src/gateway/server.models-voicewake-misc.e2e.test.ts b/src/gateway/server.models-voicewake-misc.e2e.test.ts
index 9b9bc657b4b..a89e9250270 100644
--- a/src/gateway/server.models-voicewake-misc.e2e.test.ts
+++ b/src/gateway/server.models-voicewake-misc.e2e.test.ts
@@ -10,6 +10,7 @@ import { resolveCanvasHostUrl } from "../infra/canvas-host-url.js";
 import { GatewayLockError } from "../infra/gateway-lock.js";
 import { getActivePluginRegistry, setActivePluginRegistry } from "../plugins/runtime.js";
 import { createOutboundTestPlugin } from "../test-utils/channel-plugins.js";
+import { captureEnv } from "../test-utils/env.js";
 import { GATEWAY_CLIENT_MODES, GATEWAY_CLIENT_NAMES } from "../utils/message-channel.js";
 import { createRegistry } from "./server.e2e-registry-helpers.js";
 import {
@@ -301,31 +302,24 @@ describe("gateway server models + voicewake", () => {
 
 describe("gateway server misc", () => {
   test("hello-ok advertises the gateway port for canvas host", async () => {
-    const prevToken = process.env.OPENCLAW_GATEWAY_TOKEN;
-    const prevCanvasPort = process.env.OPENCLAW_CANVAS_HOST_PORT;
-    process.env.OPENCLAW_GATEWAY_TOKEN = "secret";
-    testTailnetIPv4.value = "100.64.0.1";
-    testState.gatewayBind = "lan";
-    const canvasPort = await getFreePort();
-    testState.canvasHostPort = canvasPort;
-    process.env.OPENCLAW_CANVAS_HOST_PORT = String(canvasPort);
+    const envSnapshot = captureEnv(["OPENCLAW_CANVAS_HOST_PORT", "OPENCLAW_GATEWAY_TOKEN"]);
+    try {
+      process.env.OPENCLAW_GATEWAY_TOKEN = "secret";
+      testTailnetIPv4.value = "100.64.0.1";
+      testState.gatewayBind = "lan";
+      const canvasPort = await getFreePort();
+      testState.canvasHostPort = canvasPort;
+      process.env.OPENCLAW_CANVAS_HOST_PORT = String(canvasPort);
 
-    const testPort = await getFreePort();
-    const canvasHostUrl = resolveCanvasHostUrl({
-      canvasPort,
-      requestHost: `100.64.0.1:${testPort}`,
-      localAddress: "127.0.0.1",
-    });
-    expect(canvasHostUrl).toBe(`http://100.64.0.1:${canvasPort}`);
-    if (prevToken === undefined) {
-      delete process.env.OPENCLAW_GATEWAY_TOKEN;
-    } else {
-      process.env.OPENCLAW_GATEWAY_TOKEN = prevToken;
-    }
-    if (prevCanvasPort === undefined) {
-      delete process.env.OPENCLAW_CANVAS_HOST_PORT;
-    } else {
-      process.env.OPENCLAW_CANVAS_HOST_PORT = prevCanvasPort;
+      const testPort = await getFreePort();
+      const canvasHostUrl = resolveCanvasHostUrl({
+        canvasPort,
+        requestHost: `100.64.0.1:${testPort}`,
+        localAddress: "127.0.0.1",
+      });
+      expect(canvasHostUrl).toBe(`http://100.64.0.1:${canvasPort}`);
+    } finally {
+      envSnapshot.restore();
     }
   });