diff --git a/Duplicati/Library/Utility/ThrottledStream.cs b/Duplicati/Library/Utility/ThrottledStream.cs
index 7f30856ec..5a681baec 100644
--- a/Duplicati/Library/Utility/ThrottledStream.cs
+++ b/Duplicati/Library/Utility/ThrottledStream.cs
@@ -153,7 +153,8 @@ namespace Duplicati.Library.Utility
 		/// <param name="offset">The offset into the buffer.</param>
 		/// <param name="count">The number of bytes to write.</param>
         public override void Write(byte[] buffer, int offset, int count)
-        {
+		{
+			int bytesWritten = 0;
 			while (count > 0)
 			{
                 // To avoid excessive waiting, the delay will wait at most 2 seconds,
@@ -161,10 +162,10 @@ namespace Duplicati.Library.Utility
                 UpdateLimits();
 				var chunksize = (int)Math.Min(count, m_writespeed <= 0 ? count : m_writespeed * 2);
 				DelayIfRequired(ref m_writespeed, chunksize, ref m_last_write_sample, ref m_current_write_counter, ref m_current_write_speed);
-				m_basestream.Write(buffer, offset, chunksize);
+				m_basestream.Write(buffer, offset + bytesWritten, chunksize);
 
 				m_current_write_counter += chunksize;
-
+				bytesWritten += chunksize;
 				count -= chunksize;
 			}
         }