diff --git a/contrib/gcc-git-customization.sh b/contrib/gcc-git-customization.sh
index 6f8f23deebf..aca61b781ff 100755
--- a/contrib/gcc-git-customization.sh
+++ b/contrib/gcc-git-customization.sh
@@ -28,7 +28,7 @@ git config alias.gcc-undescr \!"f() { o=\$(git config --get gcc-config.upstream)
 git config alias.gcc-verify '!f() { "`git rev-parse --show-toplevel`/contrib/gcc-changelog/git_check_commit.py" $@; } ; f'
 git config alias.gcc-backport '!f() { "`git rev-parse --show-toplevel`/contrib/git-backport.py" $@; } ; f'
 git config alias.gcc-mklog '!f() { "`git rev-parse --show-toplevel`/contrib/mklog.py" $@; } ; f'
-git config alias.gcc-commit-mklog '!f() { "`git rev-parse --show-toplevel`/contrib/git-commit-mklog.py" $@; }; f'
+git config alias.gcc-commit-mklog '!f() { "`git rev-parse --show-toplevel`/contrib/git-commit-mklog.py" "$@"; }; f'
 
 # Make diff on MD files use "(define" as a function marker.
 # Use this in conjunction with a .gitattributes file containing
diff --git a/contrib/git-commit-mklog.py b/contrib/git-commit-mklog.py
index 9c59fb97809..eda3fc4a892 100755
--- a/contrib/git-commit-mklog.py
+++ b/contrib/git-commit-mklog.py
@@ -37,6 +37,8 @@ if __name__ == '__main__':
                         help='Add the specified PRs (comma separated)')
     parser.add_argument('-p', '--fill-up-bug-titles', action='store_true',
                         help='Download title of mentioned PRs')
+    parser.add_argument('--co',
+                        help='Add Co-Authored-By trailer (comma separated)')
     args, unknown_args = parser.parse_known_args()
 
     myenv['GCC_FORCE_MKLOG'] = '1'
@@ -49,5 +51,9 @@ if __name__ == '__main__':
     if mklog_args:
         myenv['GCC_MKLOG_ARGS'] = ' '.join(mklog_args)
 
+    if args.co:
+        for author in args.co.split(','):
+            unknown_args.append(f'--trailer "Co-Authored-By: {author}"')
+
     commit_args = ' '.join(unknown_args)
     subprocess.run(f'git commit {commit_args}', shell=True, env=myenv)
diff --git a/contrib/mklog.py b/contrib/mklog.py
index d2aea85c7cc..d362be5ab10 100755
--- a/contrib/mklog.py
+++ b/contrib/mklog.py
@@ -40,6 +40,7 @@ from unidiff import PatchSet
 
 LINE_LIMIT = 100
 TAB_WIDTH = 8
+CO_AUTHORED_BY_PREFIX = 'co-authored-by: '
 
 pr_regex = re.compile(r'(\/(\/|\*)|[Cc*!])\s+(?P<pr>PR [a-z+-]+\/[0-9]+)')
 prnum_regex = re.compile(r'PR (?P<comp>[a-z+-]+)/(?P<num>[0-9]+)')
@@ -317,6 +318,12 @@ def update_copyright(data):
                 f.write(content)
 
 
+def skip_line_in_changelog(line):
+    if line.lower().startswith(CO_AUTHORED_BY_PREFIX) or line.startswith('#'):
+        return False
+    return True
+
+
 if __name__ == '__main__':
     parser = argparse.ArgumentParser(description=help_message)
     parser.add_argument('input', nargs='?',
@@ -350,7 +357,7 @@ if __name__ == '__main__':
                                     args.fill_up_bug_titles, args.pr_numbers)
         if args.changelog:
             lines = open(args.changelog).read().split('\n')
-            start = list(takewhile(lambda l: not l.startswith('#'), lines))
+            start = list(takewhile(skip_line_in_changelog, lines))
             end = lines[len(start):]
             with open(args.changelog, 'w') as f:
                 if not start or not start[0]: