diff --git a/homeassistant/components/stream/core.py b/homeassistant/components/stream/core.py
index 076eb3596d7..cac4aa1eccb 100644
--- a/homeassistant/components/stream/core.py
+++ b/homeassistant/components/stream/core.py
@@ -8,6 +8,8 @@ from typing import Any, Callable
 
 from aiohttp import web
 import attr
+import av.container
+import av.video
 
 from homeassistant.components.http import HomeAssistantView
 from homeassistant.core import HomeAssistant, callback
@@ -24,9 +26,9 @@ class StreamBuffer:
     """Represent a segment."""
 
     segment: io.BytesIO = attr.ib()
-    output = attr.ib()  # type=av.OutputContainer
-    vstream = attr.ib()  # type=av.VideoStream
-    astream = attr.ib(default=None)  # type=Optional[av.AudioStream]
+    output: av.container.OutputContainer = attr.ib()
+    vstream: av.video.VideoStream = attr.ib()
+    astream = attr.ib(default=None)  # type=Optional[av.audio.AudioStream]
 
 
 @attr.s