diff --git a/mp3/client.py b/mp3/client.py
index 6bef4dadc0142ff6c84bfd0f51f707495c2c8b31..b600bb9e445e72869b8ac8d85ca64d01a49dd025 100644
--- a/mp3/client.py
+++ b/mp3/client.py
@@ -53,7 +53,7 @@ def bind():
 
 
 def send_operation(operation_str, socket):
-    msg = operation_str.encode(ENCODING_FORMAT)
+    msg = operation_str.upper().encode(ENCODING_FORMAT)  # todo: upper case
     msg_length = len(msg)
     # send_length = str(msg_length).encode(ENCODING_FORMAT)
     msg += b' ' * (MSG_LENGTH - msg_length)