diff --git a/lib/outputrequirementslib.php b/lib/outputrequirementslib.php
index bf45fdb2912..79da0c086c7 100644
--- a/lib/outputrequirementslib.php
+++ b/lib/outputrequirementslib.php
@@ -362,6 +362,12 @@ class page_requirements_manager {
         if ($url instanceof moodle_url) {
             return $url;
         } else if (strpos($url, '/') === 0) {
+            // Fix the admin links if needed.
+            if ($CFG->admin !== 'admin') {
+                if (strpos($url, "/admin/") === 0) {
+                    $url = preg_replace("|^/admin/|", "/$CFG->admin/", $url);
+                }
+            }
             if (debugging()) {
                 // check file existence only when in debug mode
                 if (!file_exists($CFG->dirroot . strtok($url, '?'))) {