diff --git a/neptune/experiments.py b/neptune/experiments.py
index 96956b35c..99f9f1ecf 100644
--- a/neptune/experiments.py
+++ b/neptune/experiments.py
@@ -580,7 +580,11 @@ def log_artifact(self, artifact, destination=None):
                 If ``None`` is passed, an artifact file name will be used.
 
         Note:
-            If you provide `io.StringIO`, it will be encoded in 'utf-8' before sent to Neptune.
+            If you use in-memory buffers like `io.StringIO` or `io.BytesIO`, remember that in typical case when you
+            write to such a buffer, it's current position is set to the end of the stream, so in order to read it's
+            content, you need to move back it's position to the beginning.
+            We recommend to call seek(0) on the in-memory buffers before passing it to Neptune.
+            Additionally, if you provide `io.StringIO`, it will be encoded in 'utf-8' before sent to Neptune.
 
         Raises:
             `FileNotFound`: When ``artifact`` file was not found.
diff --git a/neptune/internal/storage/datastream.py b/neptune/internal/storage/datastream.py
index 9fdd5833c..45c430cf8 100644
--- a/neptune/internal/storage/datastream.py
+++ b/neptune/internal/storage/datastream.py
@@ -77,7 +77,7 @@ def generate(self, chunk_size=BYTES_IN_ONE_MB):
                 last_offset = new_offset
             else:
                 if last_offset == 0:
-                    yield FileChunk(chunk, 0, 0)
+                    yield FileChunk(b'', 0, 0)
                 break
 
     def close(self):