diff --git a/video_decoder.py b/video_decoder.py
index ee55172..e28a950 100644
--- a/video_decoder.py
+++ b/video_decoder.py
@@ -28,7 +28,7 @@ class VideoDecoder(PyOperator):
 
     def __init__(self, start_time=None, end_time=None, sample_type=None, args=None) -> None:
         super().__init__()
-        self._start_time = start_time
+        self._start_time = start_time if start_time is not None else 0
         self._end_time = end_time
         self._sample_type = sample_type
         self._args = args if args is not None else {}