diff --git a/test/lint/check-doc.py b/test/lint/check-doc.py
index 5ff0546d7..e0f3388bb 100755
--- a/test/lint/check-doc.py
+++ b/test/lint/check-doc.py
@@ -1,82 +1,81 @@
 #!/usr/bin/env python3
 # Copyright (c) 2015-2016 The Bitcoin Core developers
 # Copyright (c) 2019 The Bitcoin developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 '''
 This checks if all command line args are documented.
 Return value is 0 to indicate no error.
 
 Author: @MarcoFalke
 '''
 
 from subprocess import check_output
 from pprint import PrettyPrinter
 import re
-import sys
 
 FOLDER_SRC = 'src'
 FOLDER_TEST = 'src/test/'
 PATH_SRC = '`git rev-parse --show-toplevel`/{}'.format(FOLDER_SRC)
 PATH_TEST = '`git rev-parse --show-toplevel`/{}'.format(FOLDER_TEST)
 
 GREP_ARGS_REGEX = r"egrep -rIzo '((Is|Get)(Bool)?Arg(s|Set)?\((\s)*)\"\-[^\"]+?\"' {}"
 CMD_GREP_ARGS_SRC = GREP_ARGS_REGEX.format(PATH_SRC)
 CMD_GREP_ARGS_TEST = GREP_ARGS_REGEX.format(PATH_TEST)
 CMD_GREP_DOCS = r"egrep -rIzo 'HelpMessageOpt\((\s)*\"\-[^\"=]+?(=|\")' {}".format(
     PATH_SRC)
 
 REGEX_ARG = re.compile(
     r'(?:(?:Is|Get)(?:Bool)?Arg(?:s|Set)?\((?:\s)*)\"(\-[^\"]+?)\"')
 REGEX_DOC = re.compile(r'HelpMessageOpt\((?:\s)*\"(\-[^\"=]+?)(?:=|\")')
 
 # list unsupported, deprecated and duplicate args as they need no documentation
 SET_DOC_OPTIONAL = set(['-benchmark',
                         '-blockminsize',
                         '-dbcrashratio',
                         '-debugnet',
                         '-forcecompactdb',
                         # TODO remove after the may 2019 fork
                         '-greatwallactivationtime',
                         '-help',
                         '-parkdeepreorg',
                         '-promiscuousmempoolflags',
                         '-replayprotectionactivationtime',
                         '-rpcssl',
                         '-socks',
                         '-tor',
                         '-whitelistalwaysrelay'])
 
 # list false positive unknows arguments
 SET_FALSE_POSITIVE_UNKNOWNS = set(['-nodebug',
                                    '-zmqpubhashblock',
                                    '-zmqpubhashtx',
                                    '-zmqpubrawblock',
                                    '-zmqpubrawtx'])
 
 
 def main():
     used = check_output(CMD_GREP_ARGS_SRC, shell=True).decode()
     tested = check_output(CMD_GREP_ARGS_TEST, shell=True).decode()
     docd = check_output(CMD_GREP_DOCS, shell=True).decode()
 
     args_used = set(re.findall(REGEX_ARG, used))
     args_used -= set(re.findall(REGEX_ARG, tested))
     args_used |= SET_FALSE_POSITIVE_UNKNOWNS
     args_docd = set(re.findall(REGEX_DOC, docd))
     args_need_doc = args_used - args_docd - SET_DOC_OPTIONAL
     args_unknown = args_docd - args_used
 
     pp = PrettyPrinter()
     print("Args used        : {}".format(len(args_used)))
     print("Args documented  : {}".format(len(args_docd)))
     print("Args undocumented: {} ({} don't need documentation)".format(
         len(args_need_doc), len(SET_DOC_OPTIONAL)))
     pp.pprint(args_need_doc)
     print("Args unknown     : {}".format(len(args_unknown)))
     pp.pprint(args_unknown)
 
 
 if __name__ == "__main__":
     main()