diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 32d55768235..de6186327f9 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -6576,6 +6576,12 @@
             "url": "/_mozilla/mozilla/interfaces.html"
           }
         ],
+        "mozilla/interfaces.worker.js": [
+          {
+            "path": "mozilla/interfaces.worker.js",
+            "url": "/_mozilla/mozilla/interfaces.worker"
+          }
+        ],
         "mozilla/lenient_this.html": [
           {
             "path": "mozilla/lenient_this.html",
diff --git a/tests/wpt/mozilla/tests/mozilla/interfaces.html b/tests/wpt/mozilla/tests/mozilla/interfaces.html
index ac5d564bef8..9ccdbe882ec 100644
--- a/tests/wpt/mozilla/tests/mozilla/interfaces.html
+++ b/tests/wpt/mozilla/tests/mozilla/interfaces.html
@@ -3,64 +3,14 @@
 <title>Interfaces exposed on the window</title>
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
+<script src="interfaces.js"></script>
 <script>
-// This is a list of all interfaces that are exposed to every webpage.
+// This is a list of interfaces that are exposed to every webpage.
 // Please only add things to this list with great care and proper review
 // from the associated module peers.
 
-// IMPORTANT: Do not change this list without review from
-//            a JavaScript Engine peer!
-var ecmaGlobals = [
-  "Array",
-  "ArrayBuffer",
-  "Atomics",
-  "Boolean",
-  "Crypto",
-  "DataView",
-  "Date",
-  "Error",
-  "EvalError",
-  "Float32Array",
-  "Float64Array",
-  "Function",
-  "Infinity",
-  "Int16Array",
-  "Int32Array",
-  "Int8Array",
-  "InternalError",
-  "Iterator",
-  "JSON",
-  "Map",
-  "Math",
-  "NaN",
-  "Number",
-  "Object",
-  "Proxy",
-  "RangeError",
-  "ReferenceError",
-  "Reflect",
-  "RegExp",
-  "SIMD",
-  "Set",
-  "SharedArrayBuffer",
-  "StopIteration",
-  "String",
-  "Symbol",
-  "SyntaxError",
-  "TypeError",
-  "TypedObject",
-  "URIError",
-  "Uint16Array",
-  "Uint32Array",
-  "Uint8Array",
-  "Uint8ClampedArray",
-  "Uint8ClampedArray",
-  "WeakMap",
-  "WeakSet",
-];
-
 // IMPORTANT: Do not change the list below without review from a DOM peer!
-var interfaceNamesInGlobalScope = [
+test_interfaces([
   "Attr",
   "BeforeUnloadEvent",
   "Blob",
@@ -234,44 +184,5 @@ var interfaceNamesInGlobalScope = [
   "XMLHttpRequest",
   "XMLHttpRequestEventTarget",
   "XMLHttpRequestUpload",
-];
-
-function createInterfaceMap() {
-  var interfaceMap = {};
-
-  function addInterfaces(interfaces)
-  {
-    for (var entry of interfaces) {
-      interfaceMap[entry] = true;
-    }
-  }
-
-  addInterfaces(ecmaGlobals);
-  addInterfaces(interfaceNamesInGlobalScope);
-  addInterfaces(["EventWatcher"]);
-  return interfaceMap;
-}
-
-test(function() {
-  var interfaceMap = createInterfaceMap();
-  for (var name of Object.getOwnPropertyNames(window)) {
-    if (!/^[A-Z]/.test(name)) {
-      continue;
-    }
-    assert_true(name in interfaceMap,
-                "If this is failing: DANGER, are you sure you want to expose the new " +
-                "interface " + name + " to all webpages as a property on the window? " +
-                "Do not make a change to this file without review from jdm or Ms2ger " +
-                "for that specific change!");
-    if (name in interfaceMap) {
-      delete interfaceMap[name];
-    }
-  }
-  for (var name of Object.keys(interfaceMap)) {
-    assert_true(name in window, name + " should be defined on the global scope");
-  }
-  assert_equals(Object.keys(interfaceMap).length, 0,
-                "The following interface(s) are not enumerated: " +
-                Object.keys(interfaceMap).join(", "));
-});
+]);
 </script>
diff --git a/tests/wpt/mozilla/tests/mozilla/interfaces.js b/tests/wpt/mozilla/tests/mozilla/interfaces.js
new file mode 100644
index 00000000000..4e1ecf8b918
--- /dev/null
+++ b/tests/wpt/mozilla/tests/mozilla/interfaces.js
@@ -0,0 +1,87 @@
+function test_interfaces(interfaceNamesInGlobalScope) {
+  test(function() {
+    // This is a list of interfaces that are exposed to every webpage by SpiderMonkey.
+    // IMPORTANT: Do not change this list without review from a JavaScript Engine peer!
+    var ecmaGlobals = [
+      "Array",
+      "ArrayBuffer",
+      "Atomics",
+      "Boolean",
+      "Crypto",
+      "DataView",
+      "Date",
+      "Error",
+      "EvalError",
+      "Float32Array",
+      "Float64Array",
+      "Function",
+      "Infinity",
+      "Int16Array",
+      "Int32Array",
+      "Int8Array",
+      "InternalError",
+      "Iterator",
+      "JSON",
+      "Map",
+      "Math",
+      "NaN",
+      "Number",
+      "Object",
+      "Proxy",
+      "RangeError",
+      "ReferenceError",
+      "Reflect",
+      "RegExp",
+      "SIMD",
+      "Set",
+      "SharedArrayBuffer",
+      "StopIteration",
+      "String",
+      "Symbol",
+      "SyntaxError",
+      "TypeError",
+      "TypedObject",
+      "URIError",
+      "Uint16Array",
+      "Uint32Array",
+      "Uint8Array",
+      "Uint8ClampedArray",
+      "Uint8ClampedArray",
+      "WeakMap",
+      "WeakSet",
+    ];
+
+    var sources = [
+      ecmaGlobals,
+      interfaceNamesInGlobalScope,
+      ["EventWatcher"],
+    ];
+
+    var interfaceMap = {};
+    for (var source of sources) {
+      for (var entry of source) {
+        interfaceMap[entry] = true;
+      }
+    }
+
+    for (var name of Object.getOwnPropertyNames(self)) {
+      if (!/^[A-Z]/.test(name)) {
+        continue;
+      }
+      assert_true(name in interfaceMap,
+                  "If this is failing: DANGER, are you sure you want to expose the new " +
+                  "interface " + name + " to all webpages as a property on the global? " +
+                  "Do not make a change to this file without review from jdm or Ms2ger " +
+                  "for that specific change!");
+      if (name in interfaceMap) {
+        delete interfaceMap[name];
+      }
+    }
+    for (var name of Object.keys(interfaceMap)) {
+      assert_true(name in self, name + " should be defined on the global scope");
+    }
+    assert_equals(Object.keys(interfaceMap).length, 0,
+                  "The following interface(s) are not enumerated: " +
+                  Object.keys(interfaceMap).join(", "));
+  });
+}
diff --git a/tests/wpt/mozilla/tests/mozilla/interfaces.worker.js b/tests/wpt/mozilla/tests/mozilla/interfaces.worker.js
new file mode 100644
index 00000000000..47c9e6a6052
--- /dev/null
+++ b/tests/wpt/mozilla/tests/mozilla/interfaces.worker.js
@@ -0,0 +1,185 @@
+importScripts("/resources/testharness.js");
+importScripts("interfaces.js");
+
+// This is a list of interfaces that are exposed to every web worker.
+// Please only add things to this list with great care and proper review
+// from the associated module peers.
+
+// IMPORTANT: Do not change the list below without review from a DOM peer!
+test_interfaces([
+  "Attr",
+  "BeforeUnloadEvent",
+  "Blob",
+  "CanvasGradient",
+  "CanvasRenderingContext2D",
+  "CanvasPattern",
+  "CharacterData",
+  "CloseEvent",
+  "CSS",
+  "CSSStyleDeclaration",
+  "DOMPoint",
+  "DOMPointReadOnly",
+  "DOMQuad",
+  "DOMRect",
+  "DOMRectReadOnly",
+  "Comment",
+  "Console",
+  "CustomEvent",
+  "DedicatedWorkerGlobalScope",
+  "Document",
+  "DocumentFragment",
+  "DocumentType",
+  "DOMException",
+  "DOMImplementation",
+  "DOMParser",
+  "DOMTokenList",
+  "DOMStringMap",
+  "Element",
+  "ErrorEvent",
+  "Event",
+  "EventSource",
+  "EventTarget",
+  "File",
+  "FileList",
+  "FileReader",
+  "FocusEvent",
+  "FormData",
+  "HashChangeEvent",
+  "HTMLAnchorElement",
+  "HTMLAppletElement",
+  "HTMLAreaElement",
+  "HTMLAudioElement",
+  "HTMLBaseElement",
+  "HTMLBodyElement",
+  "HTMLBRElement",
+  "HTMLButtonElement",
+  "HTMLCanvasElement",
+  "HTMLCollection",
+  "HTMLDataElement",
+  "HTMLDataListElement",
+  "HTMLDetailsElement",
+  "HTMLDialogElement",
+  "HTMLDirectoryElement",
+  "HTMLDivElement",
+  "HTMLDListElement",
+  "HTMLElement",
+  "HTMLEmbedElement",
+  "HTMLFieldSetElement",
+  "HTMLFontElement",
+  "HTMLFormControlsCollection",
+  "HTMLFormElement",
+  "HTMLFrameElement",
+  "HTMLFrameSetElement",
+  "HTMLHeadElement",
+  "HTMLHeadingElement",
+  "HTMLHRElement",
+  "HTMLHtmlElement",
+  "HTMLIFrameElement",
+  "HTMLImageElement",
+  "HTMLInputElement",
+  "HTMLLabelElement",
+  "HTMLLegendElement",
+  "HTMLLIElement",
+  "HTMLLinkElement",
+  "HTMLMapElement",
+  "HTMLMediaElement",
+  "HTMLMetaElement",
+  "HTMLMeterElement",
+  "HTMLModElement",
+  "HTMLObjectElement",
+  "HTMLOListElement",
+  "HTMLOptGroupElement",
+  "HTMLOptionElement",
+  "HTMLOutputElement",
+  "HTMLParagraphElement",
+  "HTMLParamElement",
+  "HTMLPreElement",
+  "HTMLProgressElement",
+  "HTMLQuoteElement",
+  "HTMLScriptElement",
+  "HTMLSelectElement",
+  "HTMLSourceElement",
+  "HTMLSpanElement",
+  "HTMLStyleElement",
+  "HTMLTableCaptionElement",
+  "HTMLTableCellElement",
+  "HTMLTableColElement",
+  "HTMLTableDataCellElement",
+  "HTMLTableElement",
+  "HTMLTableHeaderCellElement",
+  "HTMLTableRowElement",
+  "HTMLTableSectionElement",
+  "HTMLTemplateElement",
+  "HTMLTextAreaElement",
+  "HTMLTimeElement",
+  "HTMLTitleElement",
+  "HTMLTrackElement",
+  "HTMLUListElement",
+  "HTMLUnknownElement",
+  "HTMLVideoElement",
+  "ImageData",
+  "Image",
+  "KeyboardEvent",
+  "Location",
+  "MediaError",
+  "MessageEvent",
+  "MimeType",
+  "MimeTypeArray",
+  "MouseEvent",
+  "NamedNodeMap",
+  "Navigator",
+  "Node",
+  "NodeFilter",
+  "NodeIterator",
+  "NodeList",
+  "PageTransitionEvent",
+  "Performance",
+  "PerformanceTiming",
+  "Plugin",
+  "PluginArray",
+  "PopStateEvent",
+  "ProcessingInstruction",
+  "ProgressEvent",
+  "RadioNodeList",
+  "Range",
+  "Screen",
+  "Storage",
+  "StorageEvent",
+  "StyleSheet",
+  "StyleSheetList",
+  "Text",
+  "TextDecoder",
+  "TextEncoder",
+  "Touch",
+  "TouchEvent",
+  "TouchList",
+  "TreeWalker",
+  "UIEvent",
+  "URL",
+  "URLSearchParams",
+  "ValidityState",
+  "WebGLRenderingContext",
+  "WebGLUniformLocation",
+  "WebGLBuffer",
+  "WebGLContextEvent",
+  "WebGLFramebuffer",
+  "WebGLRenderbuffer",
+  "WebGLTexture",
+  "WebGLProgram",
+  "WebGLShader",
+  "WebGLObject",
+  "WebGLActiveInfo",
+  "WebGLShaderPrecisionFormat",
+  "WebSocket",
+  "Window",
+  "Worker",
+  "WorkerGlobalScope",
+  "WorkerLocation",
+  "WorkerNavigator",
+  "XMLDocument",
+  "XMLHttpRequest",
+  "XMLHttpRequestEventTarget",
+  "XMLHttpRequestUpload",
+]);
+
+done();