diff --git a/grade/edit/letter/index.php b/grade/edit/letter/index.php
index 393afe4..dedd4bf 100644
--- a/grade/edit/letter/index.php
+++ b/grade/edit/letter/index.php
@@ -141,7 +141,7 @@ if (!$edit) {
         if (!$admin and empty($data->override)) {
             $records = $DB->get_records('grade_letters', array('contextid' => $context->id));
             foreach ($records as $record) {
-                $DB->delete_record('grade_letters', array('id' => $record->id));
+                $DB->delete_records('grade_letters', array('id' => $record->id));
                 // Trigger the letter grade deleted event.
                 $event = \core\event\grade_letter_deleted::create(array(
                     'objectid' => $record->id,
diff --git a/lib/gradelib.php b/lib/gradelib.php
index cb31417..9e37c42 100644
--- a/lib/gradelib.php
+++ b/lib/gradelib.php
@@ -1401,7 +1401,7 @@ function remove_grade_letters($context, $showfeedback) {
 
     $records = $DB->get_records('grade_letters', array('contextid' => $context->id));
     foreach ($records as $record) {
-        $DB->delete_record('grade_letters', array('id' => $record->id));
+        $DB->delete_records('grade_letters', array('id' => $record->id));
         // Trigger the letter grade deleted event.
         $event = \core\event\grade_letter_deleted::create(array(
             'objectid' => $record->id,
@@ -1473,7 +1473,7 @@ function grade_course_category_delete($categoryid, $newparentid, $showfeedback)
     $context = context_coursecat::instance($categoryid);
     $records = $DB->get_records('grade_letters', array('contextid' => $context->id));
     foreach ($records as $record) {
-        $DB->delete_record('grade_letters', array('id' => $record->id));
+        $DB->delete_records('grade_letters', array('id' => $record->id));
         // Trigger the letter grade deleted event.
         $event = \core\event\grade_letter_deleted::create(array(
             'objectid' => $record->id,