diff --git a/static/WebStorage.mjs b/static/WebStorage.mjs
index 452ebef..b112770 100644
--- a/static/WebStorage.mjs
+++ b/static/WebStorage.mjs
@@ -67,12 +67,14 @@ export default class WebStorage {
                 }
             }
         }
-        return this.#fetch(resource, options).then(
-            response => {
+        return this.#fetch(resource, options)
+            .then(async response => {
+                if (response.status >= 500) {
+                    throw new Error(response.statusText + '\n' + await response.text())
+                }
                 this.#cache.put(resource, response)
                 return response
-            },
-            error => {
+            }).catch(error => {
                 console.warn(error)
                 return this.#cache.match(resource)
             }