diff --git a/gobblin-metrics-libs/gobblin-metrics-base/src/main/avro/GaaSObservabilityEventExperimental.avsc b/gobblin-metrics-libs/gobblin-metrics-base/src/main/avro/GaaSObservabilityEventExperimental.avsc
index 605e961dbd3..887d322f7d2 100644
--- a/gobblin-metrics-libs/gobblin-metrics-base/src/main/avro/GaaSObservabilityEventExperimental.avsc
+++ b/gobblin-metrics-libs/gobblin-metrics-base/src/main/avro/GaaSObservabilityEventExperimental.avsc
@@ -136,6 +136,7 @@
         "null",
         "string"
       ],
+      "default": null,
       "doc": "The instance of GaaS that is sending the event (if multiple GaaS instances are running)"
     },
     {
@@ -144,6 +145,7 @@
         "null",
         "string"
       ],
+      "default": null,
       "doc": "The job properties GaaS sends to the job executor. This is a JSON string of the job properties"
     },
     {
@@ -239,7 +241,8 @@
             ]
           }
         }
-      ]
+      ],
+      "default": null
     }
   ]
 }