diff --git a/LibOneM2M/OneM2M_Functions.ttcn b/LibOneM2M/OneM2M_Functions.ttcn
index 3a4899a8350f67a620c68a992bd2357cea0dc76d..e3c4b019a83d2594d8838d8845d8f7807ae1726f 100644
--- a/LibOneM2M/OneM2M_Functions.ttcn
+++ b/LibOneM2M/OneM2M_Functions.ttcn
@@ -5675,7 +5675,7 @@ module OneM2M_Functions {
 						}
 					}
 					case ("MqttSetDefaultTopicToNotRegistration") {
-						acPort.send(AcRequestPrimitive:{p_event, {charstring := oct2str(unichar2oct(p_originator))}});
+						acPort.send(AcRequestPrimitive:{p_event, {charstring := oct2char(unichar2oct(p_originator))}});
 					}
 					case ("MqttSetDefaultTopicToRegistration") {
 						acPort.send(AcRequestPrimitive:{p_event, {charstring := int2str(p_resourceIndex)}});