diff --git a/dom/media/test/mochitest.ini b/dom/media/test/mochitest.ini
index 434eae35879f..4306421ade4a 100644
--- a/dom/media/test/mochitest.ini
+++ b/dom/media/test/mochitest.ini
@@ -804,6 +804,8 @@ tags=promise-play
 tags=promise-play
 [test_play_promise_3.html]
 tags=promise-play
+[test_play_promise_4.html]
+tags=promise-play
 [test_play_twice.html]
 # Seamonkey: Bug 598252
 skip-if = appname == "seamonkey"
diff --git a/dom/media/test/test_play_promise_4.html b/dom/media/test/test_play_promise_4.html
new file mode 100644
index 000000000000..79b28a5d5b00
--- /dev/null
+++ b/dom/media/test/test_play_promise_4.html
@@ -0,0 +1,41 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Media test: promise-based play() method</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+  <script type="text/javascript" src="manifest.js"></script>
+  <script type="text/javascript" src="play_promise.js"></script>
+</head>
+<body>
+<pre id="test">
+
+<script>
+// Name: playNotSupportedContent
+// Case: invoke play() on an element with an unsupported content
+// Expected result: reject the promise with NotSupportedError DOM exception
+
+let manager = new MediaTestManager;
+
+function initTest(test, token) {
+  manager.started(token);
+
+  let element = document.createElement(getMajorMimeType(test.type));
+  element.src = getNotSupportedFile(test.name);
+  element.play().then(
+    (result) => {
+      ok(false, `${token} is resolved with ${result}.`);
+    },
+    (error) => {
+      if (error.name == "NotSupportedError") {
+        ok(true, `${token} is rejected with ${error.name}.`);
+      } else {
+        ok(false, `${token} is rejected with ${error.name}.`);
+      }
+    }
+  ).then( () => { manager.finished(token); } );
+}
+
+manager.runTests(gSmallTests, initTest);
+
+</script>
\ No newline at end of file
