diff --git a/TL.php b/TL.php
index de31ba7e..eb1aab33 100644
Binary files a/TL.php and b/TL.php differ
diff --git a/TL.py b/TL.py
index caa2d6a5..e16bf0c1 100644
--- a/TL.py
+++ b/TL.py
@@ -101,7 +101,7 @@ def serialize_param(bytes_io, type_, value):
     elif type_ in ["int128", "int256"]:
         assert isinstance(value, bytes)
         bytes_io.write(value)
-    elif type_ == 'string' or 'bytes':
+    elif type_ == 'string' or type_ == 'bytes':
         l = len(value)
         if l < 254: # short string format
             bytes_io.write(struct.pack('<b', l))  # 1 byte of string
diff --git a/mtproto.php b/mtproto.php
index 982e3964..4334b149 100755
Binary files a/mtproto.php and b/mtproto.php differ
diff --git a/mtproto.py b/mtproto.py
index 869b157d..ccb0c750 100644
--- a/mtproto.py
+++ b/mtproto.py
@@ -40,7 +40,6 @@ def vis(bs):
     if not len(bs) % symbols_in_one_line == 0:
         print(str((i+1)*symbols_in_one_line)+" | "+" ".join(["%02X" % b for b in bs[(i+1)*symbols_in_one_line:]])+"\n") # for last line
 
-vis(b'ddd')
 class Session:
     """ Manages TCP Transport. encryption and message frames """
     def __init__(self, ip, port, auth_key=None, server_salt=None):