diff --git a/code/reference/ch_wireshark/TCPFlowControlDemo/client.py b/code/reference/ch_wireshark/TCPFlowControlDemo/client.py
index de8f653..d500a28 100644
--- a/code/reference/ch_wireshark/TCPFlowControlDemo/client.py
+++ b/code/reference/ch_wireshark/TCPFlowControlDemo/client.py
@@ -1,5 +1,5 @@
 import socket
-import time
+import time  
 
 ip_port = ("server", 9999)
 data = "0123456789\n"*100