diff --git a/docs/websockets.md b/docs/websockets.md
index ab6a0532a0..85ec5dbbd3 100644
--- a/docs/websockets.md
+++ b/docs/websockets.md
@@ -39,7 +39,7 @@ For example: `websocket.headers['sec-websocket-version']`
 
 #### Query Parameters
 
-Headers are exposed as an immutable multi-dict.
+Query parameters are exposed as an immutable multi-dict.
 
 For example: `websocket.query_params['search']`
 
diff --git a/starlette/endpoints.py b/starlette/endpoints.py
index 2ba68c04b1..1071fc3540 100644
--- a/starlette/endpoints.py
+++ b/starlette/endpoints.py
@@ -43,7 +43,7 @@ async def method_not_allowed(self, request: Request) -> Response:
 
 class WebSocketEndpoint:
 
-    encoding = None  # May be "text", "bytes", or "json".
+    encoding: typing.Optional[str] = None  # May be "text", "bytes", or "json".
 
     def __init__(self, scope: Scope, receive: Receive, send: Send) -> None:
         assert scope["type"] == "websocket"