diff --git a/demo/image_demo.py b/demo/image_demo.py
index 183f238..f4847f8 100755
--- a/demo/image_demo.py
+++ b/demo/image_demo.py
@@ -6,9 +6,9 @@ from mmseg.core.evaluation import get_palette
 
 def main():
     parser = ArgumentParser()
-    parser.add_argument('img', help='Image file')
-    parser.add_argument('config', help='Config file')
-    parser.add_argument('checkpoint', help='Checkpoint file')
+    parser.add_argument('--img', help='Image file', default="XX")
+    parser.add_argument('--config', help='Config file', default="XX")
+    parser.add_argument('--checkpoint', help='Checkpoint file', default="XX")
     parser.add_argument(
         '--device', default='cuda:0', help='Device used for inference')
     parser.add_argument(