diff --git a/CRM/Contact/Form/Task/TaiwanACHExportTransaction.php b/CRM/Contact/Form/Task/TaiwanACHExportTransaction.php
index 9fc382b13..f40003fcc 100644
--- a/CRM/Contact/Form/Task/TaiwanACHExportTransaction.php
+++ b/CRM/Contact/Form/Task/TaiwanACHExportTransaction.php
@@ -43,7 +43,7 @@ function setDefaultValues() {
     return $defaults;
   }
 
-  public function formRule($fields, $files, $self) {
+  public static function formRule($fields, $files, $self) {
     return parent::formRule($fields, $files, $self);
   }
   public function postProcess() {