diff --git a/src/iec61850/client/ied_connection.c b/src/iec61850/client/ied_connection.c
index bc8e9ff6..d64fc595 100644
--- a/src/iec61850/client/ied_connection.c
+++ b/src/iec61850/client/ied_connection.c
@@ -1,7 +1,7 @@
 /*
  *  ied_connection.c
  *
- *  Copyright 2013-2022 Michael Zillgith
+ *  Copyright 2013-2023 Michael Zillgith
  *
  *  This file is part of libIEC61850.
  *
@@ -108,6 +108,9 @@ iedConnection_mapMmsErrorToIedError(MmsError mmsError)
     case MMS_ERROR_ACCESS_TEMPORARILY_UNAVAILABLE:
         return IED_ERROR_TEMPORARILY_UNAVAILABLE;
 
+    case MMS_ERROR_SERVICE_OBJECT_CONSTRAINT_CONFLICT:
+        return IED_ERROR_OBJECT_CONSTRAINT_CONFLICT;
+
     default:
         return IED_ERROR_UNKNOWN;
     }
diff --git a/src/iec61850/common/iec61850_common.c b/src/iec61850/common/iec61850_common.c
index fa9a13c0..2ba1d3f7 100644
--- a/src/iec61850/common/iec61850_common.c
+++ b/src/iec61850/common/iec61850_common.c
@@ -768,7 +768,6 @@ MmsMapping_ObjectReferenceToVariableAccessSpec(char* objectReference)
     return accessSpec;
 }
 
-
 static int
 getNumberOfDigits(int value)
 {
diff --git a/src/iec61850/inc/iec61850_client.h b/src/iec61850/inc/iec61850_client.h
index 1326c1e7..5e53efe2 100644
--- a/src/iec61850/inc/iec61850_client.h
+++ b/src/iec61850/inc/iec61850_client.h
@@ -162,6 +162,9 @@ typedef enum {
     /** Received an invalid response message from the server */
     IED_ERROR_MALFORMED_MESSAGE = 34,
 
+    /** Service was not executed because required resource is still in use */
+    IED_ERROR_OBJECT_CONSTRAINT_CONFLICT = 35,
+
     /** Service not implemented */
     IED_ERROR_SERVICE_NOT_IMPLEMENTED = 98,
 
diff --git a/src/mms/iso_mms/client/mms_client_connection.c b/src/mms/iso_mms/client/mms_client_connection.c
index a9763c08..6f743b0b 100644
--- a/src/mms/iso_mms/client/mms_client_connection.c
+++ b/src/mms/iso_mms/client/mms_client_connection.c
@@ -436,7 +436,17 @@ convertServiceErrorToMmsError(MmsServiceError serviceError)
         break;
 
     case 4: /* class: service */
-        mmsError = MMS_ERROR_SERVICE_OTHER;
+
+        switch (serviceError.errorCode)
+        {
+        case 5:
+            mmsError = MMS_ERROR_SERVICE_OBJECT_CONSTRAINT_CONFLICT;
+            break;
+
+        default:
+            mmsError = MMS_ERROR_SERVICE_OTHER;
+            break;
+        }
         break;
 
     case 5: /* class: service-preempt */