diff --git a/Orm/Xtensive.Orm/Tuples/TupleDescriptor.cs b/Orm/Xtensive.Orm/Tuples/TupleDescriptor.cs
index f9df212e46..eb6ff9f99c 100644
--- a/Orm/Xtensive.Orm/Tuples/TupleDescriptor.cs
+++ b/Orm/Xtensive.Orm/Tuples/TupleDescriptor.cs
@@ -121,7 +121,6 @@ public override int GetHashCode()
 
     public void GetObjectData(SerializationInfo info, StreamingContext context)
     {
-      info.AddValue("FieldCount", FieldCount);
       info.AddValue("ValuesLength", ValuesLength);
       info.AddValue("ObjectsLength", ObjectsLength);
 
@@ -286,7 +285,6 @@ private TupleDescriptor(Type[] fieldTypes)
 
     public TupleDescriptor(SerializationInfo info, StreamingContext context)
     {
-      var fieldCount = info.GetInt32("FieldCount");
       ValuesLength = info.GetInt32("ValuesLength");
       ObjectsLength = info.GetInt32("ObjectsLength");