diff --git a/specification/eventhub/resource-manager/Microsoft.EventHub/preview/2018-01-01-preview/networkrulessets-preview.json b/specification/eventhub/resource-manager/Microsoft.EventHub/preview/2018-01-01-preview/networkrulessets-preview.json
index ec6f1f0a20c5..bf62ec9aa4a3 100644
--- a/specification/eventhub/resource-manager/Microsoft.EventHub/preview/2018-01-01-preview/networkrulessets-preview.json
+++ b/specification/eventhub/resource-manager/Microsoft.EventHub/preview/2018-01-01-preview/networkrulessets-preview.json
@@ -177,6 +177,10 @@
           "description": "NetworkRuleSet properties",
           "x-ms-client-flatten": true,
           "properties": {
+            "trustedServiceAccessEnabled": {
+              "type": "boolean",
+              "description": "Value that indicates whether Trusted Service Access is Enabled or not."
+            },
             "defaultAction": {
               "type": "string",
               "description": "Default Action for Network Rule Set",