diff --git a/dom/webidl/URL.webidl b/dom/webidl/URL.webidl
index c9657b47be02f..b04e8f58e7b46 100644
--- a/dom/webidl/URL.webidl
+++ b/dom/webidl/URL.webidl
@@ -40,6 +40,7 @@ interface URL {
   USVString toJSON();
 };
 
+[Exposed=(Window,DedicatedWorker,SharedWorker)]
 partial interface URL {
   [Throws]
   static DOMString createObjectURL(Blob blob);
@@ -47,10 +48,8 @@ partial interface URL {
   static void revokeObjectURL(DOMString url);
   [ChromeOnly, Throws]
   static boolean isValidURL(DOMString url);
-};
 
-// https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html
-partial interface URL {
+  // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html
   [Throws]
   static DOMString createObjectURL(MediaSource source);
 };
diff --git a/testing/web-platform/tests/service-workers/service-worker/resources/interfaces-worker.sub.js b/testing/web-platform/tests/service-workers/service-worker/resources/interfaces-worker.sub.js
index 10fe14d5becd0..56bc8af445d5e 100644
--- a/testing/web-platform/tests/service-workers/service-worker/resources/interfaces-worker.sub.js
+++ b/testing/web-platform/tests/service-workers/service-worker/resources/interfaces-worker.sub.js
@@ -93,3 +93,7 @@ test(function() {
 test(() => {
     assert_false('XMLHttpRequest' in self);
   }, 'xhr is not exposed');
+
+test(() => {
+    assert_false('createObjectURL' in self.URL);
+  }, 'URL.createObjectURL is not exposed')