diff --git a/OpenAPI/TS28312_IntentNrm.yaml b/OpenAPI/TS28312_IntentNrm.yaml
index 108b4509ae1cdce5623f75df911d773e1679c038..575f97efdfb3c7617a238b6ff6c325bbcab2bb6a 100644
--- a/OpenAPI/TS28312_IntentNrm.yaml
+++ b/OpenAPI/TS28312_IntentNrm.yaml
@@ -530,9 +530,14 @@ components:
               - FEASIBLE
               - INFEASIBLE
         infeasibilityReasons:
-          type: string
-          readOnly: true
-          description: An attribute which is used when feasibilityCheckResult is INFEASIBLE
+          description: An attribute which is used when feasibilityCheckResult is INFEASIBLE 
+          type: array
+          items:
+            type: string
+            readOnly: true      
+            enum:
+               - INVALID_INTENT_EXPRESSION
+               - INTENT_CONFLICT
         inFeasibleExpectationInfos:
           type: array
           items: