diff --git a/OneM2M_Types.ttcn b/OneM2M_Types.ttcn
index 53e425ae127f562895b3d2d17e01e3e5270f2669..986dc0a4607939061f0174c6c0a2bc66d960f047 100644
--- a/OneM2M_Types.ttcn
+++ b/OneM2M_Types.ttcn
@@ -8974,8 +8974,9 @@ type record UtDesc {
 type record AeSimuComponentDesc {
 	/**
 	 * @desc Test System AE-ID with AE-ID-Stem format (relative) according to TS-0001-7.2-1
+	 * Note: Use omit when no value is specified instead of empty string
 	 */			
-	XSD.ID aeIdStem,
+	XSD.ID aeIdStem optional,
 	/**
 	 * @desc Test System APP-ID with App-ID format according to TS-0001-7.2-1
 	 */