diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 56ba4ef3f9c..384a9ca0db2 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -113,6 +113,7 @@ define('PARAM_BOOL',    0x0800);  //convert to value 1 or 0 using empty()
  */
 define('PAGE_COURSE_VIEW', 'course-view');
 define('PAGE_QUIZ_VIEW',   'mod-quiz-view');
+define('PAGE_CHAT_VIEW',   'mod-chat-view');
 
 /// PARAMETER HANDLING ////////////////////////////////////////////////////