diff --git a/src/robot_interface/endpoints/video_sender.py b/src/robot_interface/endpoints/video_sender.py
index d744e4a..f3e28f2 100644
--- a/src/robot_interface/endpoints/video_sender.py
+++ b/src/robot_interface/endpoints/video_sender.py
@@ -3,6 +3,7 @@ import threading
 import logging
 
 import numpy as np
+import struct
 
 from robot_interface.endpoints.socket_base import SocketBase
 from robot_interface.state import state
@@ -63,8 +64,8 @@ class VideoSender(SocketBase):
                         width = img[0]
                         height = img[1]
 
-                        width_bytes = width.to_bytes(4, 'little')
-                        height_bytes = height.to_bytes(4, 'little')
+                        width_bytes = struct.pack('<I', width)
+                        height_bytes = struct.pack('<I', height)
 
                         self.socket.send_multipart([width_bytes, height_bytes, raw_data])
                 except:
diff --git a/test/unit/test_video_sender.py b/test/unit/test_video_sender.py
index 430f658..35d592e 100644
--- a/test/unit/test_video_sender.py
+++ b/test/unit/test_video_sender.py
@@ -1,5 +1,6 @@
 # coding=utf-8
 
+import struct
 import mock
 import pytest
 import zmq
@@ -48,8 +49,10 @@ def test_video_streaming(zmq_context, mocker):
     # Pepper's image buffer lives at index 6
     mocker.patch.object(settings.video_config, "image_buffer", 6)
 
+    test_width = 320
+    test_height = 240
     mock_video_service = mock.Mock()
-    mock_video_service.getImageRemote.return_value = [None]*6 + ["fake_img"]
+    mock_video_service.getImageRemote.return_value = [test_width, test_height, None, None, None, None, b"fake_img"]
 
     fake_session = mock.Mock()
     fake_session.service.return_value = mock_video_service
@@ -63,12 +66,16 @@ def test_video_streaming(zmq_context, mocker):
 
     sender = VideoSender(zmq_context)
     send_socket = mock.Mock()
-    sender.socket.send = send_socket
+    sender.socket.send_multipart = send_socket
 
     sender.start_video_rcv()
     sender.video_rcv_loop(mock_video_service, "stream_name")
 
-    send_socket.assert_called_with("fake_img")
+    send_socket.assert_called_with([
+    struct.pack('<I', 320),
+    struct.pack('<I', 240),
+    b"fake_img"
+])
 
 
 def test_video_receive_error(zmq_context, mocker):
@@ -91,7 +98,7 @@ def test_video_receive_error(zmq_context, mocker):
 
     sender = VideoSender(zmq_context)
     send_socket = mock.Mock()
-    sender.socket.send = send_socket
+    sender.socket.send_multipart = send_socket
 
     sender.start_video_rcv()
     sender.video_rcv_loop(mock_video_service, "stream_name")