diff --git a/src/EditableSpamProtectionField.php b/src/EditableSpamProtectionField.php
index 323a47a..0424a1c 100644
--- a/src/EditableSpamProtectionField.php
+++ b/src/EditableSpamProtectionField.php
@@ -127,7 +127,7 @@ protected function getCandidateFields()
      *
      * {@inheritDoc}
      */
-    public function onBeforeWrite()
+    protected function onBeforeWrite()
     {
         $fieldMap = json_decode($this->SpamFieldSettings ?? '', true);
         if (empty($fieldMap)) {