diff --git a/streamtg.py b/streamtg.py
index 660da4e..af37c62 100644
--- a/streamtg.py
+++ b/streamtg.py
@@ -110,6 +110,14 @@ async def handler(request):
                     }
                 )
             status = 206
+        else:
+            return web.Response(status=416,
+                text='Unknown range type',
+                headers={
+                    'Content-Range': f'bytes */{max_size}',
+                    'Accept-Ranges': 'bytes'
+                }
+            )
     length = end - offset + 1
     headers = {
         'Content-Range': f'bytes {offset}-{end}/{max_size}',