diff --git a/src/py/libcamera/gen-py-formats.py b/src/py/libcamera/gen-py-formats.py
index 0ff1d12a..6323e237 100755
--- a/src/py/libcamera/gen-py-formats.py
+++ b/src/py/libcamera/gen-py-formats.py
@@ -37,7 +37,7 @@ def main(argv):
                         help='Template file name.')
     args = parser.parse_args(argv[1:])
 
-    with open(args.input, encoding='utf-8') as f:
+    with open(args.input, 'rb') as f:
         formats = yaml.safe_load(f)['formats']
 
     data = generate(formats)