Scanning fails for "zip" files

[gabrielgutunoi]

Error log:
[ERROR] UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe0 in position 276: invalid continuation byte
Traceback (most recent call last):
File "/var/task/scan.py", line 236, in lambda_handler
scan_result, scan_signature = clamav.scan_file(file_path)
File "/var/task/clamav.py", line 195, in scan_file
output = av_proc.communicate()[0].decode()

Curious enough when created from same file 2 archives (one zip and one rar) the rar file is scanned with success.