diff --git a/testing/web-platform/meta/MANIFEST.json b/testing/web-platform/meta/MANIFEST.json
index 84997c046fc0..f473b99bc4db 100644
--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -286741,6 +286741,11 @@
      {}
     ]
    ],
+   "workers/support/iframe_sw_dataUrl.html": [
+    [
+     {}
+    ]
+   ],
    "workers/support/name-as-accidental-global.js": [
     [
      {}
@@ -352264,6 +352269,12 @@
      {}
     ]
    ],
+   "workers/SharedWorker_dataUrl.html": [
+    [
+     "/workers/SharedWorker_dataUrl.html",
+     {}
+    ]
+   ],
    "workers/WorkerGlobalScope_ErrorEvent_colno.htm": [
     [
      "/workers/WorkerGlobalScope_ErrorEvent_colno.htm",
@@ -581861,6 +581872,10 @@
    "d74620a63e7d911ef60b995cabf6b360c2c46a4f",
    "testharness"
   ],
+  "workers/SharedWorker_dataUrl.html": [
+   "f65d3caef416775c970a554448cebdf02580428f",
+   "testharness"
+  ],
   "workers/WorkerGlobalScope_ErrorEvent_colno.htm": [
    "8ceb41543f928c918010000d638099faeb674980",
    "testharness"
@@ -582865,6 +582880,10 @@
    "b0e679dd7720701364abeaca6870d94db5d7ee74",
    "support"
   ],
+  "workers/support/iframe_sw_dataUrl.html": [
+   "2cd66112b612e7b861af00af5ccc26cc7c5a76f8",
+   "support"
+  ],
   "workers/support/name-as-accidental-global.js": [
    "530670268fae610b60066773ee475743b8498b53",
    "support"
diff --git a/testing/web-platform/tests/workers/SharedWorker_dataUrl.html b/testing/web-platform/tests/workers/SharedWorker_dataUrl.html
new file mode 100644
index 000000000000..c1dec27d49f8
--- /dev/null
+++ b/testing/web-platform/tests/workers/SharedWorker_dataUrl.html
@@ -0,0 +1,63 @@
+<!DOCTYPE html>
+<title>Shared Worker: Data URL cross-origin checks</title>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+</body>
+<script>
+
+function dirname(path) {
+  return path.replace(/\/[^\/]*$/, '/');
+}
+
+promise_test(t => {
+  return new Promise(function(resolve) {
+    let count = 0;
+    onmessage = e => {
+      assert_equals(e.data, 1);
+      if (++count == 2) {
+        resolve(true);
+      }
+    };
+
+    let iframeA = document.createElement('iframe');
+    document.body.appendChild(iframeA);
+    iframeA.src =  get_host_info().HTTP_REMOTE_ORIGIN +
+                   dirname(location.pathname) +
+                   "support/iframe_sw_dataUrl.html";
+
+    let iframeB = document.createElement('iframe');
+    document.body.appendChild(iframeB);
+    iframeB.src =  get_host_info().HTTPS_REMOTE_ORIGIN +
+                   dirname(location.pathname) +
+                   "support/iframe_sw_dataUrl.html";
+  });
+}, 'Data URL not shared by cross-origin SharedWorkers');
+
+promise_test(t => {
+  return new Promise(function(resolve) {
+    let count = 0;
+    onmessage = e => {
+      assert_equals(e.data, ++count);
+      if (count == 2) {
+        resolve(true);
+      }
+    };
+
+    let iframeA = document.createElement('iframe');
+    document.body.appendChild(iframeA);
+    iframeA.src =  get_host_info().HTTP_ORIGIN +
+                   dirname(location.pathname) +
+                   "support/iframe_sw_dataUrl.html";
+
+    let iframeB = document.createElement('iframe');
+    document.body.appendChild(iframeB);
+    iframeB.src =  get_host_info().HTTP_ORIGIN +
+                   dirname(location.pathname) +
+                   "support/iframe_sw_dataUrl.html";
+  });
+}, 'Data URLs shared by same-origin SharedWorkers');
+
+</script>
+</html>
diff --git a/testing/web-platform/tests/workers/support/iframe_sw_dataUrl.html b/testing/web-platform/tests/workers/support/iframe_sw_dataUrl.html
new file mode 100644
index 000000000000..0fb0ec228079
--- /dev/null
+++ b/testing/web-platform/tests/workers/support/iframe_sw_dataUrl.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<title>Iframe for Shared Worker: Data URL cross-origin checks</title>
+<body>
+<script>
+
+let worker = new SharedWorker('data:text/javascript,let conns=0; onconnect = e => { e.ports[0].postMessage(++conns); }');
+worker.port.onmessage = e => {
+  parent.postMessage(e.data, '*');
+}
+
+</script>
+</body>
+</html>
