diff --git a/CHANGES.md b/CHANGES.md
index 9ef5cb465bf57dadf77959909a234c4a8c534ce3..4ae8daad90ce8d42ce14143b3118ac4ebfc91032 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -4,6 +4,10 @@ moodle-theme_boost_campus
 Changes
 -------
 
+### Unreleased
+
+* 2021-09-16 - Regression: The switch role functionality caused a fatal error with some theme configurations - Thanks to Klaus Steitz.
+
 ### v3.10-r8
 
 * 2021-08-17 - Bugfix: The timed info banner had a wrong CSS ID - Credits to Tim Schroeder.
diff --git a/locallib.php b/locallib.php
index c0ad08a5d84606a32d1edf07923a0259c93239de..0270e766c8effa37394b7660058f839ae3387641 100644
--- a/locallib.php
+++ b/locallib.php
@@ -542,6 +542,9 @@ function theme_boost_campus_show_timed_banner_on_selected_page($now, $timedibsho
 function theme_boost_campus_get_course_information_banners() {
     global $CFG, $COURSE, $PAGE, $USER;
 
+    // Require user library.
+    require_once($CFG->dirroot.'/user/lib.php');
+
     // Initialize HTML code.
     $html = '';