diff --git a/lib/form/tags.php b/lib/form/tags.php
index 1b82f5d4c0d..93c626903fc 100644
--- a/lib/form/tags.php
+++ b/lib/form/tags.php
@@ -85,6 +85,10 @@ class MoodleQuickForm_tags extends MoodleQuickForm_group {
                 }
             }
         }
+        global $CFG;
+        if (empty($CFG->usetags)) {
+            debugging('A tags formslib field has been created even thought $CFG->usetags is false.', DEBUG_DEVELOPER);
+        }
     }
 
     protected function _load_official_tags() {