diff --git a/schemas/2020-10-15-preview/Microsoft.EventGrid.json b/schemas/2020-10-15-preview/Microsoft.EventGrid.json
index 768a4c9f25..2f07351a81 100644
--- a/schemas/2020-10-15-preview/Microsoft.EventGrid.json
+++ b/schemas/2020-10-15-preview/Microsoft.EventGrid.json
@@ -2418,7 +2418,8 @@
         "isSecret": {
           "oneOf": [
             {
-              "type": "boolean"
+              "type": "boolean",
+              "default": false
             },
             {
               "$ref": "https://schema.management.azure.com/schemas/common/definitions.json#/definitions/expression"
diff --git a/schemas/2021-06-01-preview/Microsoft.EventGrid.json b/schemas/2021-06-01-preview/Microsoft.EventGrid.json
index c0ac379f79..b51b3cc69c 100644
--- a/schemas/2021-06-01-preview/Microsoft.EventGrid.json
+++ b/schemas/2021-06-01-preview/Microsoft.EventGrid.json
@@ -2577,7 +2577,8 @@
         "isSecret": {
           "oneOf": [
             {
-              "type": "boolean"
+              "type": "boolean",
+              "default": false
             },
             {
               "$ref": "https://schema.management.azure.com/schemas/common/definitions.json#/definitions/expression"