diff --git a/OpenAPI/TS28623_SubscriptionControlNrm.yaml b/OpenAPI/TS28623_SubscriptionControlNrm.yaml
index 83b75c6b60b158f834c6bd7a703e4569a5753790..a12682a94725d7000786dd9c1a3cdfa4cbe4d561 100644
--- a/OpenAPI/TS28623_SubscriptionControlNrm.yaml
+++ b/OpenAPI/TS28623_SubscriptionControlNrm.yaml
@@ -83,7 +83,7 @@ components:
                 triggerHeartbeatNtf:
                   type: boolean
                   default: FALSE
-
+                  writeOnly: true
 #-------- Definition of YAML arrays for name-contained IOCs ----------------------
     NtfSubscriptionControl-Multiple:
       type: array