diff --git a/testing/web-platform/tests/webrtc/RTCPeerConnection-connectionState.https.html b/testing/web-platform/tests/webrtc/RTCPeerConnection-connectionState.https.html
index a6aa1cbb06fd..3c5087b93dff 100644
--- a/testing/web-platform/tests/webrtc/RTCPeerConnection-connectionState.https.html
+++ b/testing/web-platform/tests/webrtc/RTCPeerConnection-connectionState.https.html
@@ -1735,6 +1735,400 @@
 '
 )
 ;
+/
+/
+Make
+the
+callee
+act
+as
+if
+not
+bundle
+-
+aware
+async
+function
+exchangeOfferAnswerUnbundled
+(
+caller
+callee
+)
+{
+const
+offer
+=
+await
+caller
+.
+createOffer
+(
+)
+;
+const
+sdp
+=
+offer
+.
+sdp
+.
+replace
+(
+'
+BUNDLE
+'
+'
+SOMETHING
+'
+)
+.
+replace
+(
+/
+rtp
+-
+hdrext
+:
+sdes
+/
+g
+'
+rtp
+-
+hdrext
+:
+something
+'
+)
+.
+replace
+(
+/
+a
+=
+ssrc
+:
+/
+g
+'
+a
+=
+notssrc
+'
+)
+;
+await
+caller
+.
+setLocalDescription
+(
+offer
+)
+;
+await
+callee
+.
+setRemoteDescription
+(
+{
+type
+:
+'
+offer
+'
+sdp
+}
+)
+;
+await
+exchangeAnswer
+(
+caller
+callee
+)
+;
+}
+promise_test
+(
+async
+t
+=
+>
+{
+const
+pc1
+=
+new
+RTCPeerConnection
+(
+{
+bundlePolicy
+:
+'
+max
+-
+compat
+'
+}
+)
+;
+t
+.
+add_cleanup
+(
+(
+)
+=
+>
+pc1
+.
+close
+(
+)
+)
+;
+const
+pc2
+=
+new
+RTCPeerConnection
+(
+)
+;
+t
+.
+add_cleanup
+(
+(
+)
+=
+>
+pc2
+.
+close
+(
+)
+)
+;
+const
+stream
+=
+await
+getNoiseStream
+(
+{
+audio
+:
+true
+}
+)
+;
+t
+.
+add_cleanup
+(
+(
+)
+=
+>
+stream
+.
+getTracks
+(
+)
+.
+forEach
+(
+track
+=
+>
+track
+.
+stop
+(
+)
+)
+)
+;
+stream
+.
+getTracks
+(
+)
+.
+forEach
+(
+track
+=
+>
+pc1
+.
+addTrack
+(
+track
+stream
+)
+)
+;
+exchangeIceCandidates
+(
+pc1
+pc2
+)
+;
+exchangeOfferAnswerUnbundled
+(
+pc1
+pc2
+)
+;
+await
+listenToConnected
+(
+pc1
+)
+;
+/
+/
+https
+:
+/
+/
+github
+.
+com
+/
+w3c
+/
+webrtc
+-
+pc
+/
+issues
+/
+2678
+#
+issuecomment
+-
+948554126
+let
+had_intermediary_connecting
+=
+false
+let
+channel
+;
+const
+onConnectionStateChange
+=
+t
+.
+step_func
+(
+(
+)
+=
+>
+{
+const
+{
+connectionState
+iceConnectionState
+}
+=
+pc1
+;
+if
+(
+connectionState
+=
+=
+=
+'
+connecting
+'
+)
+{
+had_intermediary_connecting
+=
+true
+;
+}
+}
+)
+;
+pc1
+.
+addEventListener
+(
+'
+connectionstatechange
+'
+onConnectionStateChange
+)
+;
+channel
+=
+pc1
+.
+createDataChannel
+(
+'
+test
+'
+)
+;
+await
+exchangeOfferAnswer
+(
+pc1
+pc2
+)
+;
+await
+listenToConnected
+(
+pc1
+)
+;
+assert_true
+(
+had_intermediary_connecting
+"
+state
+should
+re
+-
+pass
+connecting
+before
+reaching
+connected
+"
+)
+;
+}
+'
+when
+adding
+a
+datachannel
+to
+an
+existing
+unbundled
+connected
+PC
+it
+should
+go
+through
+a
+connecting
+state
+'
+)
+;
 promise_test
 (
 async