diff --git a/src/node/utils/customError.js b/src/node/utils/customError.js
index c47729f7f..24ad181e6 100644
--- a/src/node/utils/customError.js
+++ b/src/node/utils/customError.js
@@ -1,3 +1,4 @@
+'use strict';
 /**
  * CustomError
  *