diff --git a/components/atoms/static_atoms.txt b/components/atoms/static_atoms.txt
index 937d0ea620efc..ebe3e89014506 100644
--- a/components/atoms/static_atoms.txt
+++ b/components/atoms/static_atoms.txt
@@ -67,6 +67,7 @@ print
 progress
 radio
 range
+ratechange
 readystatechange
 reftest-wait
 rejectionhandled
diff --git a/components/script/dom/htmlmediaelement.rs b/components/script/dom/htmlmediaelement.rs
index 7246ea90c5b44..4a32b28e55819 100644
--- a/components/script/dom/htmlmediaelement.rs
+++ b/components/script/dom/htmlmediaelement.rs
@@ -164,6 +164,10 @@ pub struct HTMLMediaElement {
     error: MutNullableDom<MediaError>,
     /// <https://html.spec.whatwg.org/multipage/#dom-media-paused>
     paused: Cell<bool>,
+    /// <https://html.spec.whatwg.org/multipage/#dom-media-defaultplaybackrate>
+    defaultPlaybackRate: Cell<f64>,
+    /// <https://html.spec.whatwg.org/multipage/#dom-media-playbackrate>
+    playbackRate: Cell<f64>,
     /// <https://html.spec.whatwg.org/multipage/#attr-media-autoplay>
     autoplaying: Cell<bool>,
     /// <https://html.spec.whatwg.org/multipage/#delaying-the-load-event-flag>
@@ -235,6 +239,8 @@ impl HTMLMediaElement {
             fired_loadeddata_event: Cell::new(false),
             error: Default::default(),
             paused: Cell::new(true),
+            defaultPlaybackRate: Cell::new(1.0),
+            playbackRate: Cell::new(1.0),
             // FIXME(nox): Why is this initialised to true?
             autoplaying: Cell::new(true),
             delaying_the_load_event_flag: Default::default(),
@@ -960,7 +966,7 @@ impl HTMLMediaElement {
         }
 
         // Step 7.
-        // FIXME(nox): Set playbackRate to defaultPlaybackRate.
+        self.playbackRate.set(self.defaultPlaybackRate.get());
 
         // Step 8.
         self.error.set(None);
@@ -1350,6 +1356,38 @@ impl HTMLMediaElementMethods for HTMLMediaElement {
         self.paused.get()
     }
 
+    /// https://html.spec.whatwg.org/multipage/#dom-media-defaultplaybackrate
+    fn DefaultPlaybackRate(&self) -> Finite<f64> {
+        Finite::wrap(self.defaultPlaybackRate.get())
+    }
+
+    /// https://html.spec.whatwg.org/multipage/#dom-media-defaultplaybackrate
+    fn SetDefaultPlaybackRate(&self, value: Finite<f64>) {
+        if *value != self.defaultPlaybackRate.get() {
+            self.defaultPlaybackRate.set(*value);
+
+            let window = window_from_node(self);
+            let task_source = window.task_manager().media_element_task_source();
+            task_source.queue_simple_event(self.upcast(), atom!("ratechange"), &window);
+        }
+    }
+
+    /// https://html.spec.whatwg.org/multipage/#dom-media-playbackrate
+    fn PlaybackRate(&self) -> Finite<f64> {
+        Finite::wrap(self.playbackRate.get())
+    }
+
+    /// https://html.spec.whatwg.org/multipage/#dom-media-playbackrate
+    fn SetPlaybackRate(&self, value: Finite<f64>) {
+        if *value != self.playbackRate.get() {
+            self.playbackRate.set(*value);
+
+            let window = window_from_node(self);
+            let task_source = window.task_manager().media_element_task_source();
+            task_source.queue_simple_event(self.upcast(), atom!("ratechange"), &window);
+        }
+    }
+
     // https://html.spec.whatwg.org/multipage/#dom-media-duration
     fn Duration(&self) -> f64 {
         self.duration.get()
diff --git a/components/script/dom/webidls/HTMLMediaElement.webidl b/components/script/dom/webidls/HTMLMediaElement.webidl
index d93fe067d0993..ace11aab6fede 100644
--- a/components/script/dom/webidls/HTMLMediaElement.webidl
+++ b/components/script/dom/webidls/HTMLMediaElement.webidl
@@ -42,8 +42,8 @@ interface HTMLMediaElement : HTMLElement {
   readonly attribute unrestricted double duration;
   // Date getStartDate();
   readonly attribute boolean paused;
-  // attribute double defaultPlaybackRate;
-  // attribute double playbackRate;
+  attribute double defaultPlaybackRate;
+  attribute double playbackRate;
   readonly attribute TimeRanges played;
   // readonly attribute TimeRanges seekable;
   // readonly attribute boolean ended;
diff --git a/tests/wpt/metadata/html/semantics/embedded-content/media-elements/playing-the-media-resource/playbackRate.html.ini b/tests/wpt/metadata/html/semantics/embedded-content/media-elements/playing-the-media-resource/playbackRate.html.ini
deleted file mode 100644
index 666997e01de78..0000000000000
--- a/tests/wpt/metadata/html/semantics/embedded-content/media-elements/playing-the-media-resource/playbackRate.html.ini
+++ /dev/null
@@ -1,27 +0,0 @@
-[playbackRate.html]
-  type: testharness
-  expected: TIMEOUT
-  [playbackRate initial value]
-    expected: FAIL
-
-  [setting playbackRate]
-    expected: TIMEOUT
-
-  [playbackRate set to small positive value]
-    expected: TIMEOUT
-
-  [playbackRate set to large positive value]
-    expected: TIMEOUT
-
-  [playbackRate set to small negative value]
-    expected: TIMEOUT
-
-  [playbackRate set to large negative value]
-    expected: TIMEOUT
-
-  [playbackRate set to 0]
-    expected: TIMEOUT
-
-  [playbackRate set to -1]
-    expected: TIMEOUT
-