diff --git a/extensions/browser/src/browser/config.test.ts b/extensions/browser/src/browser/config.test.ts
index e305a3669a8..5113e5ce064 100644
--- a/extensions/browser/src/browser/config.test.ts
+++ b/extensions/browser/src/browser/config.test.ts
@@ -1,9 +1,34 @@
 import { describe, expect, it } from "vitest";
-import { withEnv } from "../../test-support.js";
 import { resolveUserPath } from "../utils.js";
 import { resolveBrowserConfig, resolveProfile, shouldStartLocalBrowserServer } from "./config.js";
 import { getBrowserProfileCapabilities } from "./profile-capabilities.js";
 
+function withEnv<T>(env: Record<string, string | undefined>, fn: () => T): T {
+  const snapshot = new Map<string, string | undefined>();
+  for (const [key] of Object.entries(env)) {
+    snapshot.set(key, process.env[key]);
+  }
+
+  try {
+    for (const [key, value] of Object.entries(env)) {
+      if (value === undefined) {
+        delete process.env[key];
+      } else {
+        process.env[key] = value;
+      }
+    }
+    return fn();
+  } finally {
+    for (const [key, value] of snapshot) {
+      if (value === undefined) {
+        delete process.env[key];
+      } else {
+        process.env[key] = value;
+      }
+    }
+  }
+}
+
 describe("browser config", () => {
   it("defaults to enabled with loopback defaults and lobster-orange color", () => {
     const resolved = resolveBrowserConfig(undefined);