diff --git a/schemas/2021-10-01/Microsoft.CostManagement.json b/schemas/2021-10-01/Microsoft.CostManagement.json
index b1ceac7066..fa18d1a62c 100644
--- a/schemas/2021-10-01/Microsoft.CostManagement.json
+++ b/schemas/2021-10-01/Microsoft.CostManagement.json
@@ -818,17 +818,6 @@
           ],
           "description": "The comparison expression to be used in the report."
         },
-        "not": {
-          "oneOf": [
-            {
-              "type": "object"
-            },
-            {
-              "$ref": "https://schema.management.azure.com/schemas/common/definitions.json#/definitions/expression"
-            }
-          ],
-          "description": "The filter expression to be used in the report."
-        },
         "or": {
           "oneOf": [
             {