diff --git a/lib/deprecatedlib.php b/lib/deprecatedlib.php
index 5f72a73b197..c52eee23350 100644
--- a/lib/deprecatedlib.php
+++ b/lib/deprecatedlib.php
@@ -2838,24 +2838,10 @@ function show_event($event) {
 }
 
 /**
- * Converts string to lowercase using most compatible function available.
- *
  * @deprecated Use textlib::strtolower($text) instead.
- *
- * @param string $string The string to convert to all lowercase characters.
- * @param string $encoding The encoding on the string.
- * @return string
  */
 function moodle_strtolower($string, $encoding='') {
-
-    debugging('moodle_strtolower() is deprecated. Please use textlib::strtolower() instead.', DEBUG_DEVELOPER);
-
-    //If not specified use utf8
-    if (empty($encoding)) {
-        $encoding = 'UTF-8';
-    }
-    //Use text services
-    return textlib::strtolower($string, $encoding);
+    throw new coding_exception('moodle_strtolower() cannot be used any more. Please use textlib::strtolower() instead.');
 }
 
 /**