diff --git a/aioesphomeapi/connection.py b/aioesphomeapi/connection.py
index 0879c77..346f5f1 100644
--- a/aioesphomeapi/connection.py
+++ b/aioesphomeapi/connection.py
@@ -598,6 +598,22 @@ class APIConnection:
             return
         fut.set_exception(asyncio.TimeoutError())
 
+    def _handle_complex_message(
+        self,
+        fut: asyncio.Future[None],
+        responses: List[message.Message],
+        do_append: Optional[Callable[[message.Message], bool]],
+        do_stop: Optional[Callable[[message.Message], bool]],
+        resp: message.Message,
+    ) -> None:
+        """Handle a message that is part of a response."""
+        if fut.done():
+            return
+        if do_append is None or do_append(resp):
+            responses.append(resp)
+        if do_stop is None or do_stop(resp):
+            fut.set_result(None)
+
     async def send_message_await_response_complex(
         self,
         send_msg: message.Message,
@@ -613,7 +629,7 @@ class APIConnection:
         :param do_stop: Predicate to check if a received message is the stop response.
         :param timeout: The maximum amount of time to wait for the stop response.
 
-        :raises TimeoutAPIError: if a timeout occured
+        :raises TimeoutAPIError: if a timeout occurred
         """
         # Send the message right away to reduce latency.
         # This is safe because we are not awaiting between
@@ -622,15 +638,10 @@ class APIConnection:
         self.send_message(send_msg)
         # Unsafe to await between sending the message and registering the handler
         fut: asyncio.Future[None] = self._loop.create_future()
-        responses = []
-
-        def on_message(resp: message.Message) -> None:
-            if fut.done():
-                return
-            if do_append is None or do_append(resp):
-                responses.append(resp)
-            if do_stop is None or do_stop(resp):
-                fut.set_result(None)
+        responses: List[message.Message] = []
+        on_message = partial(
+            self._handle_complex_message, fut, responses, do_append, do_stop
+        )
 
         message_handlers = self._message_handlers
         read_exception_futures = self._read_exception_futures