diff --git a/src/main/java/org/opensearch/security/http/OnBehalfOfAuthenticator.java b/src/main/java/org/opensearch/security/http/OnBehalfOfAuthenticator.java
index 93833c5c36..8e9f29f50a 100644
--- a/src/main/java/org/opensearch/security/http/OnBehalfOfAuthenticator.java
+++ b/src/main/java/org/opensearch/security/http/OnBehalfOfAuthenticator.java
@@ -198,6 +198,7 @@ private AuthCredentials extractCredentials0(final RestRequest request) {
             }
         }
 
+        // Return null for the authentication failure
         return null;
     }