diff --git a/content.js b/content.js
index 446a951..eb10d49 100644
--- a/content.js
+++ b/content.js
@@ -77,6 +77,7 @@
       body: body.toString(),
       credentials: 'same-origin'
     });
+    if (!resp.ok) throw new Error('Offered courses request failed: ' + resp.status);
     const html = await resp.text();
     const courses = ISMIStools.parseOfferedCourses(html);
     const match = courses.find((c) => c.courseCode === courseCode);
@@ -115,6 +116,7 @@
     let header = {};
     try {
       const resp = await fetch('/Manage/Student', { credentials: 'same-origin' });
+      if (!resp.ok) throw new Error('Profile request failed: ' + resp.status);
       const html = await resp.text();
       header = ISMIStools.parseProfilePage(html);
     } catch (e) {