diff --git a/LibOneM2M/OneM2M_Functions.ttcn b/LibOneM2M/OneM2M_Functions.ttcn
index c6db8f39977b20d4d2b23b1d4d2d11f3b81ec920..c1ff591ed7211179545c787d49a7a42d77ecb27e 100644
--- a/LibOneM2M/OneM2M_Functions.ttcn
+++ b/LibOneM2M/OneM2M_Functions.ttcn
@@ -5570,7 +5570,7 @@ module OneM2M_Functions {
 						//Calculate the SP-Relative-AE-ID following format defined in TS-0010 MQTT
 						v_aeResourceAddress := f_getResourceAddress(p_aeIndex, e_nonHierarchical, e_spRelative);
 						if(vc_resourcesList[p_aeIndex].resource.aE.aE_ID[0] == "S") {
-							v_spRelativeAeIdForMqtt := f_resourceIdCleaner(v_aeResourceAddress);
+							v_spRelativeAeIdForMqtt := oct2char(unichar2oct(f_resourceIdCleaner(v_aeResourceAddress)));
 						} else {
 							v_spRelativeAeIdForMqtt := f_getSpRelativeAeIdForMqtt(v_aeResourceAddress);
 						}