diff --git a/lib/index.d.ts b/lib/index.d.ts
index 108755d..71ac030 100755
--- a/lib/index.d.ts
+++ b/lib/index.d.ts
@@ -23,6 +23,13 @@ export class Boom<Data = any> extends Error {
      */
     isServer: boolean;
 
+    /**
+     * if true, indicates that auth is missing credentials and triggers a try on the next
+     * auth strategy. See https://github.com/hapijs/boom/blob/master/API.md#boomunauthorizedmessage-scheme-attributes
+     * 
+     */
+    isMissing?: boolean;
+
     /**
      * The error message
      */