--- tcsteg3.py	2019-06-18 11:51:40.000000000 -0000
+++ tcsteg3.py	2019-06-18 11:51:40.000000000 -0000
@@ -125,7 +125,7 @@
                     f_dest.seek(bodySize - 1, 1)
                     byte = f_dest.read(1)
                     if not byte:
-                        f_dest.write("\0")
+                        f_dest.write(b"\0")
                     else:
                         f_dest.seek(-1, 1)
                         f_dest.write(byte)