diff --git a/main/admin/career_diagram.php b/main/admin/career_diagram.php
index 6a542b35b1..c03a642d56 100644
--- a/main/admin/career_diagram.php
+++ b/main/admin/career_diagram.php
@@ -11,14 +11,9 @@ use ChamiloSession as Session;
  *
  * Requires extra_field_values.value to be longtext to save diagram:
  *
-update extra_field_values set created_at = null where created_at = '0000-00-00 00:00:00';
-update extra_field_values set updated_at = null where updated_at = '0000-00-00 00:00:00';
-
 UPDATE extra_field_values SET created_at = NULL WHERE CAST(created_at AS CHAR(20)) = '0000-00-00 00:00:00';
 UPDATE extra_field_values SET updated_at = NULL WHERE CAST(updated_at AS CHAR(20)) = '0000-00-00 00:00:00';
-
-alter table extra_field_values modify column value longtext null;
-
+ALTER TABLE extra_field_values modify column value longtext null;
 */
 
 $cidReset = true;
diff --git a/main/install/configuration.dist.php b/main/install/configuration.dist.php
index 3e1da54819..bdf7ffd7b7 100755
--- a/main/install/configuration.dist.php
+++ b/main/install/configuration.dist.php
@@ -450,8 +450,12 @@ $_configuration['agenda_legend'] = [
 //$_configuration['security_referrer_policy'] = 'origin-when-cross-origin';
 // HTTP headers security section ends here
 // Add answered_at field in table survey_invitation
+// Requires DB change:
+// ALTER TABLE c_survey_invitation ADD answered_at DATETIME DEFAULT NULL;
 //$_configuration['survey_answered_at_field'] = false;
 // Allow career diagram, requires a DB change:
-// ALTER TABLE c_survey_invitation ADD answered_at DATETIME DEFAULT NULL;
+//UPDATE extra_field_values SET created_at = NULL WHERE CAST(created_at AS CHAR(20)) = '0000-00-00 00:00:00';
+//UPDATE extra_field_values SET updated_at = NULL WHERE CAST(updated_at AS CHAR(20)) = '0000-00-00 00:00:00';
+//ALTER TABLE extra_field_values modify column value longtext null;
 //$_configuration['allow_career_diagram'] = false;