diff --git a/livekit/src/rtc_engine/rtc_session.rs b/livekit/src/rtc_engine/rtc_session.rs
index fa01a69f..3b6febb0 100644
--- a/livekit/src/rtc_engine/rtc_session.rs
+++ b/livekit/src/rtc_engine/rtc_session.rs
@@ -821,7 +821,6 @@ impl SessionInner {
             }
 
             matched.append(&mut partial_matched);
-            matched.append(&mut unmatched);
 
             transceiver.set_codec_preferences(matched)?;
         }