diff --git a/v3_18_0/CDT-enumerationTypes-v3_18_0.xsd b/v3_18_0/CDT-enumerationTypes-v3_18_0.xsd
index fcb08d21566b22487b9204ecacfb73adc6548a1f..8b0fb5df32f170371f135ed7b7da028487c71d78 100644
--- a/v3_18_0/CDT-enumerationTypes-v3_18_0.xsd
+++ b/v3_18_0/CDT-enumerationTypes-v3_18_0.xsd
@@ -388,6 +388,8 @@ oneM2M EXPRESSLY ADVISES ANY AND ALL USE OF OR RELIANCE UPON THIS INFORMATION PR
 			<xs:enumeration value="4126" /> 
 			<!-- OPERATION_DENIED_BY_REMOTE_ENTITY -->
 			<xs:enumeration value="4127" />    
+			<!-- SERVICE_SUBSCRIPTION_NOT_ESTABLISHED -->
+			<xs:enumeration value="4128" />    
 			
 			<!-- INTERNAL_SERVER_ERROR     -->
 			<xs:enumeration value="5000" />