diff --git a/CMakeLists.txt b/CMakeLists.txt
index 50c7a7c7..195a20a8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -48,6 +48,7 @@ option(CONFIG_IEC61850_LOG_SERVICE "Build with support for IEC 61850 logging ser
 option(CONFIG_IEC61850_SERVICE_TRACKING "Build with support for IEC 61850 service tracking" ON)
 option(CONFIG_IEC61850_SETTING_GROUPS "Build with support for IEC 61850 setting group services" ON)
 option(CONFIG_IEC61850_SUPPORT_USER_READ_ACCESS_CONTROL "Allow user provided callback to control read access" ON)
+option(CONFIG_IEC61850_RCB_ALLOW_ONLY_PRECONFIGURED_CLIENT "allow only configured clients (when pre-configured by ClientLN)" OFF)
 
 set(CONFIG_REPORTING_DEFAULT_REPORT_BUFFER_SIZE "65536" CACHE STRING "Default buffer size for buffered reports in byte" )
 
diff --git a/config/stack_config.h.cmake b/config/stack_config.h.cmake
index dd93fcce..d3ef67b5 100644
--- a/config/stack_config.h.cmake
+++ b/config/stack_config.h.cmake
@@ -137,7 +137,7 @@
 #define CONFIG_IEC61850_BRCB_WITH_RESVTMS 1
 
 /* allow only configured clients (when pre-configured by ClientLN) - note behavior in PIXIT Rp13 */
-#define CONFIG_IEC61850_RCB_ALLOW_ONLY_PRECONFIGURED_CLIENT 0
+#cmakedefine01 CONFIG_IEC61850_RCB_ALLOW_ONLY_PRECONFIGURED_CLIENT
 
 /* The default buffer size of buffered RCBs in bytes */
 #cmakedefine CONFIG_REPORTING_DEFAULT_REPORT_BUFFER_SIZE @CONFIG_REPORTING_DEFAULT_REPORT_BUFFER_SIZE@
diff --git a/src/iec61850/server/mms_mapping/reporting.c b/src/iec61850/server/mms_mapping/reporting.c
index cbd6e3cf..677194c1 100644
--- a/src/iec61850/server/mms_mapping/reporting.c
+++ b/src/iec61850/server/mms_mapping/reporting.c
@@ -1732,17 +1732,18 @@ Reporting_RCBWriteAccessHandler(MmsMapping* self, ReportControl* rc, char* eleme
     }
 
 #if (CONFIG_IEC61850_RCB_ALLOW_ONLY_PRECONFIGURED_CLIENT == 1)
-    if (isIpAddressMatchingWithOwner(rc, MmsServerConnection_getClientAddress(connection)) == false) {
-        retVal = DATA_ACCESS_ERROR_OBJECT_ACCESS_DENIED;
+    if (rc->resvTms == -1) {
+        if (isIpAddressMatchingWithOwner(rc, MmsServerConnection_getClientAddress(connection)) == false) {
+            retVal = DATA_ACCESS_ERROR_OBJECT_ACCESS_DENIED;
 
-        if (DEBUG_IED_SERVER)
-            printf("IED_SERVER: client IP not matching with pre-assigned owner --> write access denied!\n");
+            if (DEBUG_IED_SERVER)
+                printf("IED_SERVER: client IP not matching with pre-assigned owner --> write access denied!\n");
 
-        goto exit_function;
+            goto exit_function;
+        }
     }
 #endif
 
-
     if (strcmp(elementName, "RptEna") == 0) {
 
         if (value->value.boolean == true) {
diff --git a/src/mms/iso_mms/common/mms_value.c b/src/mms/iso_mms/common/mms_value.c
index 1281c8a8..2b604f85 100644
--- a/src/mms/iso_mms/common/mms_value.c
+++ b/src/mms/iso_mms/common/mms_value.c
@@ -101,6 +101,9 @@ MmsValue_newUnsignedFromBerInteger(Asn1PrimitiveValue* berInteger)
 bool
 MmsValue_equals(const MmsValue* self, const MmsValue* otherValue)
 {
+    if ((self == NULL) || (otherValue == NULL))
+        return false;
+
     if (self->type == otherValue->type) {
         switch (self->type)
         {