diff --git a/BinaryObjectScanner/OldDotNet.cs b/BinaryObjectScanner/OldDotNet.cs
new file mode 100644
index 00000000..146332a9
--- /dev/null
+++ b/BinaryObjectScanner/OldDotNet.cs
@@ -0,0 +1,50 @@
+#if NET20 || NET35
+
+using System;
+using System.IO;
+
+namespace BinaryObjectScanner
+{
+    /// <summary>
+    /// Derived from the mscorlib code from .NET Framework 4.0
+    /// </summary>
+    internal static class OldDotNet
+    {
+        public static void CopyTo(this Stream source, Stream destination)
+        {
+            if (destination == null)
+            {
+                throw new ArgumentNullException("destination");
+            }
+
+            if (!source.CanRead && !source.CanWrite)
+            {
+                throw new ObjectDisposedException(null);
+            }
+
+            if (!destination.CanRead && !destination.CanWrite)
+            {
+                throw new ObjectDisposedException("destination");
+            }
+
+            if (!source.CanRead)
+            {
+                throw new NotSupportedException();
+            }
+
+            if (!destination.CanWrite)
+            {
+                throw new NotSupportedException();
+            }
+
+            byte[] array = new byte[81920];
+            int count;
+            while ((count = source.Read(array, 0, array.Length)) != 0)
+            {
+                destination.Write(array, 0, count);
+            }
+        }
+    }
+}
+
+#endif