diff --git a/util/locale_database/qlocalexml2cpp.py b/util/locale_database/qlocalexml2cpp.py
index fda8e182ecd..950e284baf5 100755
--- a/util/locale_database/qlocalexml2cpp.py
+++ b/util/locale_database/qlocalexml2cpp.py
@@ -17,7 +17,7 @@ The ISO 639-3 data file can be downloaded from the SIL website:
 import datetime
 import argparse
 from pathlib import Path
-from typing import Callable, Iterator, Optional
+from typing import Callable, Iterator, Optional, TextIO
 
 from qlocalexml import Locale, QLocaleXmlReader
 from localetools import *
@@ -666,7 +666,7 @@ class LocaleHeaderWriter (SourceFileEditor):
         out('\n    };\n')
 
 
-def main(argv, out, err):
+def main(argv: list[str], out: TextIO, err: TextIO) -> int:
     """Updates QLocale's CLDR data from a QLocaleXML file.
 
     Takes sys.argv, sys.stdout, sys.stderr (or equivalents) as
@@ -679,7 +679,7 @@ def main(argv, out, err):
 
     Updates various src/corelib/t*/q*_data_p.h files within the qtbase
     checkout to contain data extracted from the QLocaleXML file."""
-    calendars_map = {
+    calendars_map: dict[str, str] = {
         # CLDR name: Qt file name fragment
         'gregorian': 'roman',
         'persian': 'jalali',
@@ -700,11 +700,11 @@ def main(argv, out, err):
     parser.add_argument('--calendars', help='select calendars to emit data for',
                         nargs='+', metavar='CALENDAR',
                         choices=all_calendars, default=all_calendars)
-    args = parser.parse_args(argv[1:])
+    args: argparse.Namespace = parser.parse_args(argv[1:])
 
-    qlocalexml = args.input_file
+    qlocalexml: str = args.input_file
     qtsrcdir = Path(args.qtbase_path)
-    calendars = {cal: calendars_map[cal] for cal in args.calendars}
+    calendars: dict[str, str] = {cal: calendars_map[cal] for cal in args.calendars}
 
     if not (qtsrcdir.is_dir()
             and all(qtsrcdir.joinpath('src/corelib/text', leaf).is_file()