diff --git a/OpenAPI/TS28532_FaultMnS.yaml b/OpenAPI/TS28532_FaultMnS.yaml
index d2a61268a11a06ceef57daa3432488510b29a3aa..4388b0178e7da48b5710d7dd0f6df6d946f70684 100755
--- a/OpenAPI/TS28532_FaultMnS.yaml
+++ b/OpenAPI/TS28532_FaultMnS.yaml
@@ -792,6 +792,7 @@ components:
           required:
             - alarmId
             - alarmType
+            - probableCause
           properties:
             alarmId:
               $ref: '#/components/schemas/AlarmId'
@@ -834,6 +835,7 @@ components:
           required:
             - alarmId
             - alarmType
+            - probableCause
             - serviceUser
             - serviceProvider
             - securityAlarmDetector