diff --git a/src/borg/archiver.py b/src/borg/archiver.py
index 78fdfe7a3..e8e1568f1 100644
--- a/src/borg/archiver.py
+++ b/src/borg/archiver.py
@@ -793,7 +793,7 @@ class Archiver:
                 archive = Archive(repository, key, manifest, args.location.archive, cache=cache,
                                   consider_part_files=args.consider_part_files)
 
-                if args.format:
+                if args.format is not None:
                     format = args.format
                 elif args.short:
                     format = "{path}{NL}"
@@ -804,7 +804,7 @@ class Archiver:
                 for item in archive.iter_items(lambda item: matcher.match(item.path)):
                     write(safe_encode(formatter.format_item(item)))
         else:
-            if args.format:
+            if args.format is not None:
                 format = args.format
             elif args.short:
                 format = "{archive}{NL}"
@@ -1251,7 +1251,7 @@ class Archiver:
             for old_name, new_name, warning in deprecations:
                 if arg.startswith(old_name):
                     args[i] = arg.replace(old_name, new_name)
-                    self.print_warning(warning)
+                    print(warning, file=sys.stderr)
         return args
 
     def build_parser(self, prog=None):
diff --git a/src/borg/testsuite/archiver.py b/src/borg/testsuite/archiver.py
index 1901b8d49..bd26eeb98 100644
--- a/src/borg/testsuite/archiver.py
+++ b/src/borg/testsuite/archiver.py
@@ -1203,7 +1203,7 @@ class ArchiverTestCase(ArchiverTestCaseBase):
         self.cmd('init', self.repository_location)
         test_archive = self.repository_location + '::test'
         self.cmd('create', test_archive, src_dir)
-        self.cmd('list', '--list-format', '-', test_archive, exit_code=1)
+        self.cmd('list', '--list-format', '-', test_archive)
         self.archiver.exit_code = 0  # reset exit code for following tests
         output_1 = self.cmd('list', test_archive)
         output_2 = self.cmd('list', '--format', '{mode} {user:6} {group:6} {size:8d} {isomtime} {path}{extra}{NEWLINE}', test_archive)