diff --git a/src/azure-cli/azure/cli/command_modules/eventgrid/custom.py b/src/azure-cli/azure/cli/command_modules/eventgrid/custom.py
index eb8549ac663..d528310c747 100644
--- a/src/azure-cli/azure/cli/command_modules/eventgrid/custom.py
+++ b/src/azure-cli/azure/cli/command_modules/eventgrid/custom.py
@@ -2130,6 +2130,7 @@ def update_event_subscription(
         storage_queue_msg_ttl=None,
         enable_advanced_filtering_on_arrays=None,
         delivery_attribute_mapping=None):
+
     return _update_event_subscription_internal(
         instance=instance,
         endpoint=endpoint,
@@ -2177,7 +2178,7 @@ def _update_event_subscription_internal(  # pylint: disable=too-many-locals,too-
 
     _validate_deadletter_identity_args(
         deadletter_identity,
-        deadletter_endpoint)
+        deadletter_identity_endpoint)
 
     if (endpoint_type is not None and
             endpoint_type.lower() != WEBHOOK_DESTINATION.lower() and