--- a/dom/media/webaudio/test/test_periodicWave.html
+++ b/dom/media/webaudio/test/test_periodicWave.html
@@ -36,20 +36,19 @@ addLoadEvent(function() {
   }, DOMException.INDEX_SIZE_ERR);
   expectException(function() {
     ac.createPeriodicWave(new Float32Array(0), new Float32Array(0));
   }, DOMException.INDEX_SIZE_ERR);
   expectNoException(function() {
     ac.createPeriodicWave(new Float32Array(4097), new Float32Array(4097));
   });
 
-  // real || imag
-  expectException(function() {
+  expectNoException(function() {
     new PeriodicWave(ac, {});
-  }, DOMException.INDEX_SIZE_ERR);
+  });
 
   // real.size == imag.size
   expectException(function() {
     new PeriodicWave(ac, {real: new Float32Array(10), imag: new Float32Array(9)});
   }, DOMException.INDEX_SIZE_ERR);
 
   // 0 size is not allowed
   expectException(function() {

--- a/testing/web-platform/meta/webaudio/idlharness.https.html.ini
+++ b/testing/web-platform/meta/webaudio/idlharness.https.html.ini
@@ -159,22 +159,16 @@
     expected: FAIL
 
   [MediaStreamTrackAudioSourceNode interface: existence and properties of interface prototype object's "constructor" property]
     expected: FAIL
 
   [MediaStreamTrackAudioSourceNode interface: existence and properties of interface prototype object's @@unscopables property]
     expected: FAIL
 
-  [PeriodicWave must be primary interface of new PeriodicWave(context)]
-    expected: FAIL
-
-  [Stringification of new PeriodicWave(context)]
-    expected: FAIL
-
   [AudioWorklet interface: existence and properties of interface object]
     expected: FAIL
 
   [AudioWorklet interface object length]
     expected: FAIL
 
   [AudioWorklet interface object name]
     expected: FAIL