diff --git a/lib/core/src/server/manager/manager-config.js b/lib/core/src/server/manager/manager-config.js
index d72dde4e405..389aecec762 100644
--- a/lib/core/src/server/manager/manager-config.js
+++ b/lib/core/src/server/manager/manager-config.js
@@ -37,6 +37,12 @@ const getAutoRefs = async (options) => {
   return list.filter(Boolean);
 };
 
+const checkRef = (url) =>
+  fetch(`${url}/iframe.html`).then(
+    ({ ok }) => ok,
+    () => false
+  );
+
 const stripTrailingSlash = (url) => url.replace(/\/$/, '');
 
 const toTitle = (input) => {
@@ -96,9 +102,7 @@ async function getManagerWebpackConfig(options, presets) {
     // verify the refs are publicly reachable, if they are not we'll require stories.json at runtime, otherwise the ref won't work
     await Promise.all(
       Object.entries(refs).map(async ([k, value]) => {
-        const { ok } = await fetch(`${value.url}/iframe.html`).catch((e) => ({
-          ok: false,
-        }));
+        const ok = checkRef(value.url);
 
         refs[k] = { ...value, type: ok ? 'server-checked' : 'unknown' };
       })