diff --git a/src/Imagination.LWM2M.Common/TLV/TlvConstant.cs b/src/Imagination.LWM2M.Common/TLV/TlvConstant.cs
index 0c16131..c83eba2 100644
--- a/src/Imagination.LWM2M.Common/TLV/TlvConstant.cs
+++ b/src/Imagination.LWM2M.Common/TLV/TlvConstant.cs
@@ -31,8 +31,8 @@ public class TlvConstant
 	{
 
 		public const int CONTENT_TYPE_PLAIN = 1541; 		
-		public const int CONTENT_TYPE_TLV = 1542;
-		public const int CONTENT_TYPE_JSON = 1543;
+		public const int CONTENT_TYPE_TLV = 11542;
+		public const int CONTENT_TYPE_JSON = 11543;
 
 		internal const int RESOURCE_WITH_VALUE = 0xC0;
 		internal const int MULTIPLE_RESOURCES = 0x80;