diff --git a/test/api/domTest.js b/test/api/domTest.js
index 26f161b..235a620 100644
--- a/test/api/domTest.js
+++ b/test/api/domTest.js
@@ -55,7 +55,11 @@ for (const browser of BROWSERS) {
         30_000
       );
       const result = await driver.executeScript('return ' + bundle);
-      t.truthy(result?.advice?.info?.amp);
+      // Ordinary page, so info.amp is legitimately false — assert the
+      // bundle produced the info block, not that the page is AMP.
+      t.is(result.advice.info.amp, false);
+      t.truthy(result.advice.performance.adviceList);
+      t.is(result.url, url);
     }
   );
 }
diff --git a/test/dom/adviceTest.js b/test/dom/adviceTest.js
index 6357c47..aa5c227 100644
--- a/test/dom/adviceTest.js
+++ b/test/dom/adviceTest.js
@@ -11,6 +11,7 @@ const KEYS = [
   'advice',
   'score',
   'weight',
+  'severity',
   'offending',
   'tags'
 ];
diff --git a/test/help/webserver.js b/test/help/webserver.js
index 945e9d9..531f85d 100644
--- a/test/help/webserver.js
+++ b/test/help/webserver.js
@@ -80,7 +80,9 @@ export async function startServer(useHttp2) {
   if (!isListening) {
     await new Promise((resolveCb, rejectCb) => {
       server
-        .listen(0, '0.0.0.0')
+        // Loopback, not 0.0.0.0: the browsers run on this machine, and
+        // Firefox refuses http://0.0.0.0:port where Chrome tolerates it.
+        .listen(0, '127.0.0.1')
         .on('error', rejectCb)
         .on('listening', () => {
           isListening = true;