diff --git a/Stack/Opc.Ua.Core/Types/Encoders/BinaryDecoder.cs b/Stack/Opc.Ua.Core/Types/Encoders/BinaryDecoder.cs
index 7daeda9aa0..96e6605cd4 100644
--- a/Stack/Opc.Ua.Core/Types/Encoders/BinaryDecoder.cs
+++ b/Stack/Opc.Ua.Core/Types/Encoders/BinaryDecoder.cs
@@ -1539,6 +1539,14 @@ namespace Opc.Ua
             if (systemType != null)
             {
                 encodeable = Activator.CreateInstance(systemType) as IEncodeable;
+
+                // set type identifier for custom complex data types before decode.
+                IComplexTypeInstance complexTypeInstance = encodeable as IComplexTypeInstance;
+
+                if (complexTypeInstance != null)
+                {
+                    complexTypeInstance.TypeId = extension.TypeId;
+                }
             }
 
             // get the length.
diff --git a/Stack/Opc.Ua.Core/Types/Encoders/IComplexTypeInstance.cs b/Stack/Opc.Ua.Core/Types/Encoders/IComplexTypeInstance.cs
new file mode 100644
index 0000000000..48fbdb64dd
--- /dev/null
+++ b/Stack/Opc.Ua.Core/Types/Encoders/IComplexTypeInstance.cs
@@ -0,0 +1,28 @@
+/* Copyright (c) 1996-2016, OPC Foundation. All rights reserved.
+   The source code in this file is covered under a dual-license scenario:
+     - RCL: for OPC Foundation members in good-standing
+     - GPL V2: everybody else
+   RCL license terms accompanied with this source code. See http://opcfoundation.org/License/RCL/1.00/
+   GNU General Public License as published by the Free Software Foundation;
+   version 2 of the License are accompanied with this source code. See http://opcfoundation.org/License/GPLv2
+   This source code is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+*/
+
+namespace Opc.Ua
+{
+    /// <summary>
+    /// Interface implemented by complex data type instances.
+    /// </summary>
+    public interface IComplexTypeInstance
+    {
+        /// <summary>
+        /// Gets or sets the UA type identifier for the encodeable type.
+        /// </summary>
+        /// <value>
+        /// The UA type identifier.
+        /// </value>
+        ExpandedNodeId TypeId { get; set; }
+    }
+}