diff --git a/sdk/lib/web_audio/dart2js/web_audio_dart2js.dart b/sdk/lib/web_audio/dart2js/web_audio_dart2js.dart
index 29544d8f98c..37e538bcb70 100644
--- a/sdk/lib/web_audio/dart2js/web_audio_dart2js.dart
+++ b/sdk/lib/web_audio/dart2js/web_audio_dart2js.dart
@@ -386,7 +386,7 @@ class AudioNode extends EventTarget {
   int? get numberOfOutputs native;
 
   @JSName('connect')
-  AudioNode _connect(destination, [int? output, int? input]) native;
+  AudioNode? _connect(destination, [int? output, int? input]) native;
 
   void disconnect([destination_OR_output, int? output, int? input]) native;
 
diff --git a/tools/dom/idl/dart/dart.idl b/tools/dom/idl/dart/dart.idl
index ac5b337be53..674af140c3e 100644
--- a/tools/dom/idl/dart/dart.idl
+++ b/tools/dom/idl/dart/dart.idl
@@ -450,6 +450,15 @@ interface AudioContext {
     [DartSuppress] DelayNode createDelayNode(optional double maxDelayTime);
 };
 
+[DartSupplemental]
+interface AudioNode : EventTarget {
+    [DartSuppress] AudioNode connect(AudioNode destination, optional unsigned long output = 0, optional unsigned long input = 0);
+    [DartSuppress] void connect(AudioParam destination, optional unsigned long output = 0);
+    AudioNode? connect(AudioNode destination, optional unsigned long output = 0, optional unsigned long input = 0);
+    // Scripts don't unify return types, so this is changed from void to do so.
+    AudioNode? connect(AudioParam destination, optional unsigned long output = 0);
+};
+
 [DartSupplemental]
 interface HTMLInputElement {
     [DartSuppress] attribute boolean webkitSpeech;