diff --git a/hobo/environment/management/commands/makemessages.py b/hobo/environment/management/commands/makemessages.py
index f32bb0b..4860992 100644
--- a/hobo/environment/management/commands/makemessages.py
+++ b/hobo/environment/management/commands/makemessages.py
@@ -18,7 +18,12 @@ from django.core.management.commands import makemessages
 
 
 class Command(makemessages.Command):
+    def add_arguments(self, parser):
+        super().add_arguments(parser)
+        parser.add_argument('--keep-obsolete', action='store_true', help='Keep obsolete message strings.')
+
     def handle(self, *args, **options):
         if not options.get('add_location') and self.gettext_version >= (0, 19):
             options['add_location'] = 'file'
+        options['no_obsolete'] = not (options.get('keep_obsolete'))
         return super().handle(*args, **options)