diff --git a/src/iec61850/client/client_control.c b/src/iec61850/client/client_control.c
index ad31648d..4cd837ac 100644
--- a/src/iec61850/client/client_control.c
+++ b/src/iec61850/client/client_control.c
@@ -1285,6 +1285,12 @@ ControlObjectClient_getLastApplError(ControlObjectClient self)
     return self->lastApplError;
 }
 
+void
+ControlObjectClient_setCtlNum(ControlObjectClient self, uint8_t ctlNum)
+{
+    self->ctlNum = ctlNum;
+}
+
 void
 controlObjectClient_invokeCommandTerminationHandler(ControlObjectClient self)
 {
diff --git a/src/iec61850/inc/iec61850_client.h b/src/iec61850/inc/iec61850_client.h
index d3b58d1a..9d1946e9 100644
--- a/src/iec61850/inc/iec61850_client.h
+++ b/src/iec61850/inc/iec61850_client.h
@@ -2231,6 +2231,12 @@ ControlObjectClient_enableInterlockCheck(ControlObjectClient self);
 LIB61850_API DEPRECATED void
 ControlObjectClient_enableSynchroCheck(ControlObjectClient self);
 
+/**
+ * \deprecated Do not use (ctlNum is handled automatically by the library)! Intended for test purposes only.
+ */
+LIB61850_API DEPRECATED void
+ControlObjectClient_setCtlNum(ControlObjectClient self, uint8_t ctlNum);
+
 /**
  * \brief Set the value of the interlock check flag when a control command is sent
  *
diff --git a/src/iec61850/server/mms_mapping/control.c b/src/iec61850/server/mms_mapping/control.c
index 452ac7fc..adb57611 100644
--- a/src/iec61850/server/mms_mapping/control.c
+++ b/src/iec61850/server/mms_mapping/control.c
@@ -2144,8 +2144,6 @@ Control_writeAccessControlObject(MmsMapping* self, MmsDomain* domain, char* vari
 
             bool testCondition = MmsValue_getBoolean(test);
 
-            controlObject->testMode = testCondition;
-
             if ((controlObject->ctlModel == 2) || (controlObject->ctlModel == 4)) {
                 if (controlObject->mmsConnection != connection) {
                     indication = DATA_ACCESS_ERROR_TEMPORARILY_UNAVAILABLE;
@@ -2163,7 +2161,8 @@ Control_writeAccessControlObject(MmsMapping* self, MmsDomain* domain, char* vari
                          MmsValue_equals(origin, controlObject->origin) &&
                          MmsValue_equals(ctlNum, controlObject->ctlNum) &&
                          (controlObject->interlockCheck == interlockCheck) &&
-                         (controlObject->synchroCheck == synchroCheck)
+                         (controlObject->synchroCheck == synchroCheck) &&
+                         (controlObject->testMode == testCondition)
                          ) == false)
                     {
                         indication = DATA_ACCESS_ERROR_TYPE_INCONSISTENT;
@@ -2191,6 +2190,7 @@ Control_writeAccessControlObject(MmsMapping* self, MmsDomain* domain, char* vari
                     controlObject->synchroCheck = synchroCheck;
                     controlObject->interlockCheck = interlockCheck;
                     controlObject->mmsConnection = connection;
+                    controlObject->testMode = testCondition;
 
                     CheckHandlerResult checkResult = CONTROL_ACCEPTED;
                     if (controlObject->checkHandler != NULL) { /* perform operative tests */