diff --git a/schemas/2021-09-15-preview/Microsoft.Chaos.json b/schemas/2021-09-15-preview/Microsoft.Chaos.json
index f5f9fdb3f1..98e0bf1de9 100644
--- a/schemas/2021-09-15-preview/Microsoft.Chaos.json
+++ b/schemas/2021-09-15-preview/Microsoft.Chaos.json
@@ -32,7 +32,7 @@
           "oneOf": [
             {
               "type": "string",
-              "pattern": "^[a-zA-Z0-9_\\-\\.]+$",
+              "pattern": "^[^<>%&:?#/\\\\]+$",
               "minLength": 1
             },
             {