diff --git a/src/seedu/addressbook/AddressBook.java b/src/seedu/addressbook/AddressBook.java
index 5a158b67..5d424507 100644
--- a/src/seedu/addressbook/AddressBook.java
+++ b/src/seedu/addressbook/AddressBook.java
@@ -36,6 +36,7 @@
  **/
 public class AddressBook {
 
+    private static final String UPDATE = "change to document";
     /**
      * Default file path used if the user doesn't provide the file name.
      */