diff --git a/blog/external_blog_edit_form.php b/blog/external_blog_edit_form.php
index 1cf979b3aa6..68ca8ed7c56 100644
--- a/blog/external_blog_edit_form.php
+++ b/blog/external_blog_edit_form.php
@@ -82,7 +82,7 @@ class blog_edit_external_form extends moodleform {
         $rssfile = $rss->registry->create('File', array($data['url']));
         $filetest = $rss->registry->create('Locator', array($rssfile));
 
-        if (!$filetest->is_feed($rssfile)) {
+        if (empty($rssfile->success) || !$filetest->is_feed($rssfile)) {
             $errors['url'] = get_string('feedisinvalid', 'blog');
         } else {
             $rss->set_feed_url($data['url']);
diff --git a/blog/lib.php b/blog/lib.php
index 47566276e76..078c203811d 100644
--- a/blog/lib.php
+++ b/blog/lib.php
@@ -153,7 +153,7 @@ function blog_sync_external_entries($externalblog) {
     $rssfile = $rss->registry->create('File', array($externalblog->url));
     $filetest = $rss->registry->create('Locator', array($rssfile));
 
-    if (!$filetest->is_feed($rssfile)) {
+    if (empty($rssfile->success) || !$filetest->is_feed($rssfile)) {
         $externalblog->failedlastsync = 1;
         $DB->update_record('blog_external', $externalblog);
         return false;