diff --git a/testing/web-platform/tests/webrtc/RTCRtpEncodingParameters-codec-opus-stereo.https.html b/testing/web-platform/tests/webrtc/RTCRtpEncodingParameters-codec-opus-stereo.https.html
index 47da849fbd87..d7a378f3ca50 100644
--- a/testing/web-platform/tests/webrtc/RTCRtpEncodingParameters-codec-opus-stereo.https.html
+++ b/testing/web-platform/tests/webrtc/RTCRtpEncodingParameters-codec-opus-stereo.https.html
@@ -562,6 +562,24 @@
 remoteTrack
 )
 ;
+/
+/
+The
+stereo
+opus
+decoder
+outputs
+stereo
+regardless
+of
+the
+signal
+on
+the
+/
+/
+wire
+.
 assert_equals
 (
 await
@@ -570,13 +588,19 @@
 t
 remoteTrack
 )
-1
+2
 '
 Remote
 track
 is
-also
+stereo
+(
+despite
+local
+track
+being
 mono
+)
 '
 )
 ;
@@ -590,6 +614,11 @@
 track
 with
 opus
+(
+stereo
+decoder
+upmix
+)
 '
 )
 ;