diff --git a/src/includes/closures/Plugin/AutoCacheUtils.php b/src/includes/closures/Plugin/AutoCacheUtils.php
index 6d39399f..cc1658a8 100644
--- a/src/includes/closures/Plugin/AutoCacheUtils.php
+++ b/src/includes/closures/Plugin/AutoCacheUtils.php
@@ -132,7 +132,7 @@
 
     if (is_wp_error($head = wp_remote_head($sitemap, array('redirection' => 5)))) {
         $failure = 'WP_Http says: '.$head->get_error_message().'.';
-        if(strpos($head->get_error_message(), 'timed out') !== false || strpos($head->get_error_message(), 'timeout') !== false) { // $head->get_error_code() only returns generic `http_request_failed`
+        if(stripos($head->get_error_message(), 'timed out') !== false || stripos($head->get_error_message(), 'timeout') !== false) { // $head->get_error_code() only returns generic `http_request_failed`
             $failure .= '<br /><em>'.__('Note: Most timeout errors are resolved by refreshing the page and trying again. If timeout errors persist, please see <a href="http://zencache.com/r/kb-article-why-am-i-seeing-a-timeout-error/" target="_blank">this article</a>.', SLUG_TD).'</em>';
         }
     } elseif (empty($head['response']['code']) || (int)$head['response']['code'] >= 400) {