diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4c1be2b..bf2275b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [4.0.5] - 2025-06-18
+
+- Added missing flag to call_middleware for multichannel mode.
+
 ## [4.0.4] - 2025-06-09
 
 - Fixed non-multichannel sessions bugging out after adding multichannel support
diff --git a/VERSION b/VERSION
index 7d666cb..8b2dd6c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-4.0.4
\ No newline at end of file
+4.0.5
\ No newline at end of file
diff --git a/speechmatics/client.py b/speechmatics/client.py
index 61a2554..dcc6ff6 100644
--- a/speechmatics/client.py
+++ b/speechmatics/client.py
@@ -306,7 +306,7 @@ async def _stream_channel(self, channel, stream, queue, audio_chunk_size):
 
             # seq_no is defaultdict is so the keys are created automatically
             self.seq_no[channel] += 1
-            self._call_middleware(ClientMessageType.AddChannelAudio, message)
+            self._call_middleware(ClientMessageType.AddChannelAudio, message, False)
             await queue.put(message)
         await queue.put(self._end_of_channel(channel))