diff --git a/lib/classes/event/base.php b/lib/classes/event/base.php
index bf38916972a..b0872145605 100644
--- a/lib/classes/event/base.php
+++ b/lib/classes/event/base.php
@@ -266,6 +266,15 @@ abstract class base implements \IteratorAggregate {
             if ($expectedcourseid != $event->data['courseid']) {
                 debugging("Inconsistent courseid - context combination detected.", DEBUG_DEVELOPER);
             }
+
+            if (method_exists($event, 'get_legacy_logdata') ||
+                method_exists($event, 'set_legacy_logdata') ||
+                method_exists($event, 'get_legacy_eventname') ||
+                method_exists($event, 'get_legacy_eventdata')
+            ) {
+                debugging("Invalid event functions defined in " . $event->data['eventname'], DEBUG_DEVELOPER);
+            }
+
         }
 
         // Let developers validate their custom data (such as $this->data['other'], contextlevel, etc.).
diff --git a/lib/upgrade.txt b/lib/upgrade.txt
index 98cea6f9b14..f7895d85923 100644
--- a/lib/upgrade.txt
+++ b/lib/upgrade.txt
@@ -578,6 +578,10 @@ defined or can't be applied.
   - message_unblock_contact
   - message_block_contact
   - message_get_contact
+  - get_legacy_logdata
+  - set_legacy_logdata
+  - get_legacy_eventname
+  - get_legacy_eventdata
 * The following renamed classes have been completely removed:
     - course_in_list (now: core_course_list_element)
     - coursecat (now: core_course_category)