--- a/testing/web-platform/tests/webaudio/the-audio-api/the-delaynode-interface/delaynode-maxdelaylimit.html
+++ b/testing/web-platform/tests/webaudio/the-audio-api/the-delaynode-interface/delaynode-maxdelaylimit.html
@@ -27,21 +27,25 @@
                 1, sampleRate * renderLengthSeconds, sampleRate);
             let toneBuffer = createToneBuffer(
                 context, 20, 20 * toneLengthSeconds, sampleRate);  // 20Hz tone
 
             let bufferSource = context.createBufferSource();
             bufferSource.buffer = toneBuffer;
 
             window.context = context;
-            should(() => context.createDelay(180)).throw();
-            should(() => context.createDelay(0)).throw();
-            should(() => context.createDelay(-1)).throw();
-            should(() => context.createDelay(NaN)).throw();
-            ;
+            should(() => context.createDelay(180)).throw("NotSupportedError",
+              "Delay length cannot be 180 seconds or more");
+            should(() => context.createDelay(0)).throw("NotSupportedError",
+              "Delay length cannot be 0");
+            should(() => context.createDelay(-1)).throw("NotSupportedError",
+              "Delay length cannot be negative");
+            should(() => context.createDelay(NaN)).throw(TypeError,
+              "Delay lenght cannot be a NaN");
+
             let delay = context.createDelay(179);
             delay.delayTime.value = delayTimeSeconds;
             window.delay = delay;
             should(
                 delay.delayTime.value,
                 'delay.delayTime.value = ' + delayTimeSeconds)
                 .beEqualTo(delayTimeSeconds);