diff --git a/testing/web-platform/tests/html/semantics/popups/popup-animation-corner-cases.tentative.html b/testing/web-platform/tests/html/semantics/popups/popup-animation-corner-cases.tentative.html
index e2298fc1752b5..337346b211d3e 100644
--- a/testing/web-platform/tests/html/semantics/popups/popup-animation-corner-cases.tentative.html
+++ b/testing/web-platform/tests/html/semantics/popups/popup-animation-corner-cases.tentative.html
@@ -94,7 +94,7 @@
   assert_true(isElementVisible(popUp));
   assert_equals(popUp.getAnimations({subtree: true}).length,0);
   let animation;
-  popUp.addEventListener('hide', () => {
+  popUp.addEventListener('popuphide', () => {
     animation = popUp.animate([{opacity: 1},{opacity: 0}],1000000);
   });
   assert_equals(popUp.getAnimations({subtree: true}).length,0,'There should be no animations yet');
@@ -105,7 +105,7 @@
   animation.finish();
   await waitForRender();
   assert_false(isElementVisible(popUp),'Once the animation ends, the popup is hidden');
-},'It should be possible to use the "hide" event handler to animate the hide');
+},'It should be possible to use the "popuphide" event handler to animate the hide');
 
 
 promise_test(async (t) => {
@@ -115,7 +115,7 @@
   popUp.showPopUp();
   assert_true(isElementVisible(popUp));
   assert_equals(popUp.getAnimations({subtree: true}).length,0);
-  popUp.addEventListener('hide', () => {
+  popUp.addEventListener('popuphide', () => {
     popUp.animate([{opacity: 1},{opacity: 0}],1000000);
   });
   assert_equals(popUp.getAnimations({subtree: true}).length,0,'There should be no animations yet');
@@ -123,13 +123,13 @@
   await waitForRender();
   assert_equals(popUp.getAnimations({subtree: true}).length,1,'the hide animation should now be running');
   assert_false(isElementVisible(popUp),'But the animation should *not* keep the popup visible in this case');
-},'It should *not* be possible to use the "hide" event handler to animate the hide, if the hide is due to dialog.showModal');
+},'It should *not* be possible to use the "popuphide" event handler to animate the hide, if the hide is due to dialog.showModal');
 
 promise_test(async (t) => {
   const {popUp, descendent} = createPopUp(t,'');
   popUp.showPopUp();
   assert_true(isElementVisible(popUp));
-  popUp.addEventListener('hide', (e) => {
+  popUp.addEventListener('popuphide', (e) => {
     e.preventDefault();
   });
   popUp.hidePopUp();
diff --git a/testing/web-platform/tests/html/semantics/popups/popup-events.tentative.html b/testing/web-platform/tests/html/semantics/popups/popup-events.tentative.html
index 441980177c38b..cd24a83f6ee1a 100644
--- a/testing/web-platform/tests/html/semantics/popups/popup-events.tentative.html
+++ b/testing/web-platform/tests/html/semantics/popups/popup-events.tentative.html
@@ -11,34 +11,49 @@
 
 <script>
 window.onload = () => {
-  promise_test(async t => {
-    const popup = document.querySelector('[popup]');
-    let showCount = 0;
-    let hideCount = 0;
-    assert_false(popup.matches(':open'));
-    const controller = new AbortController();
-    const signal = controller.signal;
-    t.add_cleanup(() => controller.abort());
-    document.addEventListener('show',() => ++showCount, {signal});
-    document.addEventListener('hide',() => ++hideCount, {signal});
-    assert_equals(0,showCount);
-    assert_equals(0,hideCount);
-    popup.showPopUp();
-    assert_true(popup.matches(':open'));
-    assert_equals(1,showCount);
-    assert_equals(0,hideCount);
-    await waitForRender();
-    assert_true(popup.matches(':open'));
-    popup.hidePopUp();
-    assert_false(popup.matches(':open'));
-    assert_equals(1,showCount);
-    assert_equals(1,hideCount);
-    await waitForRender();
-    // No additional events after animation frame
-    assert_false(popup.matches(':open'));
-    assert_equals(1,showCount);
-    assert_equals(1,hideCount);
-  }, 'Show and hide events get properly dispatched for popups');
+  for(const method of ["listener","attribute"]) {
+    promise_test(async t => {
+      const popup = document.querySelector('[popup]');
+      assert_false(popup.matches(':open'));
+      let showCount = 0;
+      let hideCount = 0;
+      switch (method) {
+        case "listener":
+          const controller = new AbortController();
+          const signal = controller.signal;
+          t.add_cleanup(() => controller.abort());
+          document.addEventListener('popupshow',() => ++showCount, {signal});
+          document.addEventListener('popuphide',() => ++hideCount, {signal});
+          break;
+        case "attribute":
+          assert_false(popup.hasAttribute('onpopupshow'));
+          assert_false(popup.hasAttribute('onpopuphide'));
+          t.add_cleanup(() => popup.removeAttribute('onpopupshow'));
+          t.add_cleanup(() => popup.removeAttribute('onpopuphide'));
+          popup.onpopupshow = () => ++showCount;
+          popup.onpopuphide = () => ++hideCount;
+          break;
+        default: assert_unreached();
+      }
+      assert_equals(0,showCount);
+      assert_equals(0,hideCount);
+      popup.showPopUp();
+      assert_true(popup.matches(':open'));
+      assert_equals(1,showCount);
+      assert_equals(0,hideCount);
+      await waitForRender();
+      assert_true(popup.matches(':open'));
+      popup.hidePopUp();
+      assert_false(popup.matches(':open'));
+      assert_equals(1,showCount);
+      assert_equals(1,hideCount);
+      await waitForRender();
+      // No additional events after animation frame
+      assert_false(popup.matches(':open'));
+      assert_equals(1,showCount);
+      assert_equals(1,hideCount);
+    }, `Popupshow and popuphide events (${method}) get properly dispatched for popups`);
+  }
 
   promise_test(async t => {
     const popUp = document.querySelector('[popup]');
@@ -46,18 +61,18 @@
     const signal = controller.signal;
     t.add_cleanup(() => controller.abort());
     let cancel = true;
-    popUp.addEventListener('show',(e) => {
+    popUp.addEventListener('popupshow',(e) => {
       if (cancel)
         e.preventDefault();
     }, {signal});
     assert_false(popUp.matches(':open'));
     popUp.showPopUp();
-    assert_false(popUp.matches(':open'),'The "show" event should be cancelable');
+    assert_false(popUp.matches(':open'),'The "popupshow" event should be cancelable');
     cancel = false;
     popUp.showPopUp();
     assert_true(popUp.matches(':open'));
     popUp.hidePopUp();
     assert_false(popUp.matches(':open'));
-  }, 'Show event is cancelable');
+  }, 'Popupshow event is cancelable');
 };
 </script>
diff --git a/testing/web-platform/tests/html/semantics/popups/popup-invoking-attribute.tentative.html b/testing/web-platform/tests/html/semantics/popups/popup-invoking-attribute.tentative.html
index b676eed54056c..b281e1f4c06b1 100644
--- a/testing/web-platform/tests/html/semantics/popups/popup-invoking-attribute.tentative.html
+++ b/testing/web-platform/tests/html/semantics/popups/popup-invoking-attribute.tentative.html
@@ -175,8 +175,8 @@
 const button = document.querySelector('button');
 let showCount = 0;
 let hideCount = 0;
-popUp.addEventListener('show',() => ++showCount);
-popUp.addEventListener('hide',() => ++hideCount);
+popUp.addEventListener('popupshow',() => ++showCount);
+popUp.addEventListener('popuphide',() => ++hideCount);
 
 async function assertState(expectOpen,expectShow,expectHide) {
   assert_equals(popUp.matches(':open'),expectOpen,'Popup open state is incorrect');
diff --git a/testing/web-platform/tests/html/semantics/popups/popup-light-dismiss-on-scroll.tentative.html b/testing/web-platform/tests/html/semantics/popups/popup-light-dismiss-on-scroll.tentative.html
index d48f1b4b63fe2..b5d09883325c4 100644
--- a/testing/web-platform/tests/html/semantics/popups/popup-light-dismiss-on-scroll.tentative.html
+++ b/testing/web-platform/tests/html/semantics/popups/popup-light-dismiss-on-scroll.tentative.html
@@ -44,7 +44,7 @@
   }
   async_test(t => {
     for(let popup of popups) {
-      popup.addEventListener('hide',e => {
+      popup.addEventListener('popuphide',e => {
         assert_unreached('Scrolling should not light-dismiss a popup');
       });
     }
diff --git a/testing/web-platform/tests/html/semantics/popups/popup-light-dismiss.tentative.html b/testing/web-platform/tests/html/semantics/popups/popup-light-dismiss.tentative.html
index 7cd95d8dc23ff..8eca7a647a655 100644
--- a/testing/web-platform/tests/html/semantics/popups/popup-light-dismiss.tentative.html
+++ b/testing/web-platform/tests/html/semantics/popups/popup-light-dismiss.tentative.html
@@ -46,14 +46,14 @@
   const afterp1 = document.querySelector('#after_p1');
 
   let popup1HideCount = 0;
-  popup1.addEventListener('hide',(e) => {
+  popup1.addEventListener('popuphide',(e) => {
     ++popup1HideCount;
-    e.preventDefault(); // 'hide' should not be cancellable.
+    e.preventDefault(); // 'popuphide' should not be cancellable.
   });
   let popup2HideCount = 0;
-  popup2.addEventListener('hide',(e) => {
+  popup2.addEventListener('popuphide',(e) => {
     ++popup2HideCount;
-    e.preventDefault(); // 'hide' should not be cancellable.
+    e.preventDefault(); // 'popuphide' should not be cancellable.
   });
   promise_test(async () => {
     assert_false(popup1.matches(':open'));
diff --git a/testing/web-platform/tests/html/semantics/popups/popup-show-event.tentative.html b/testing/web-platform/tests/html/semantics/popups/popup-show-event.tentative.html
index e4775ec49b453..88f6702d4de45 100644
--- a/testing/web-platform/tests/html/semantics/popups/popup-show-event.tentative.html
+++ b/testing/web-platform/tests/html/semantics/popups/popup-show-event.tentative.html
@@ -14,7 +14,7 @@
   requestAnimationFrame(() => {++frameCount;});
   const popUp = document.querySelector('[popup]');
   const testText = 'Show Event Occurred';
-  popUp.addEventListener('show',() => {
+  popUp.addEventListener('popupshow',() => {
     popUp.textContent = testText;
   })
   popUp.offsetHeight;