diff --git a/tests/protocols/test_websocket.py b/tests/protocols/test_websocket.py
index d21be54de..2bd45b713 100644
--- a/tests/protocols/test_websocket.py
+++ b/tests/protocols/test_websocket.py
@@ -403,7 +403,11 @@ async def connect(url):
 @pytest.mark.parametrize("ws_protocol_cls", WS_PROTOCOLS)
 @pytest.mark.parametrize("http_protocol_cls", HTTP_PROTOCOLS)
 @pytest.mark.parametrize("code", [None, 1000, 1001])
-@pytest.mark.parametrize("reason", [None, "test"])
+@pytest.mark.parametrize(
+    "reason",
+    [None, "test", False],
+    ids=["none_as_reason", "normal_reason", "without_reason"],
+)
 async def test_app_close(ws_protocol_cls, http_protocol_cls, code, reason):
     async def app(scope, receive, send):
         while True:
@@ -416,7 +420,7 @@ async def app(scope, receive, send):
                 if code is not None:
                     reply["code"] = code
 
-                if reason is not None:
+                if reason is not False:
                     reply["reason"] = reason
 
                 await send(reply)
diff --git a/uvicorn/protocols/websockets/websockets_impl.py b/uvicorn/protocols/websockets/websockets_impl.py
index d829f49a6..f4fa67f29 100644
--- a/uvicorn/protocols/websockets/websockets_impl.py
+++ b/uvicorn/protocols/websockets/websockets_impl.py
@@ -261,7 +261,7 @@ async def asgi_send(self, message):
 
             elif message_type == "websocket.close":
                 code = message.get("code", 1000)
-                reason = message.get("reason", "")
+                reason = message.get("reason", "") or ""
                 await self.close(code, reason)
                 self.closed_event.set()
 
diff --git a/uvicorn/protocols/websockets/wsproto_impl.py b/uvicorn/protocols/websockets/wsproto_impl.py
index a870f1710..704d6b8cb 100644
--- a/uvicorn/protocols/websockets/wsproto_impl.py
+++ b/uvicorn/protocols/websockets/wsproto_impl.py
@@ -297,7 +297,7 @@ async def send(self, message):
             elif message_type == "websocket.close":
                 self.close_sent = True
                 code = message.get("code", 1000)
-                reason = message.get("reason", "")
+                reason = message.get("reason", "") or ""
                 self.queue.put_nowait({"type": "websocket.disconnect", "code": code})
                 output = self.conn.send(
                     wsproto.events.CloseConnection(code=code, reason=reason)