diff --git a/target-config.js b/target-config.js
index 8aef7bf..178b72f 100644
--- a/target-config.js
+++ b/target-config.js
@@ -80,7 +80,8 @@
       'test/js/group-constructors.js',
       'test/js/group-player.js',
       'test/js/group-player-finish-event.js',
-      'test/js/timeline.js');
+      'test/js/timeline.js',
+      'test/js/timing.js');
 
   // This object specifies the source and test files for different Web Animation build targets.
   var targetConfig = {
diff --git a/test/js/timing.js b/test/js/timing.js
index 7f4fb67..0bc0436 100644
--- a/test/js/timing.js
+++ b/test/js/timing.js
@@ -3,8 +3,112 @@ suite('timing-tests', function() {
     webAnimationsMinifill.timeline._players = [];
   });
 
+  test('changing timing iterations mid-animation', function() {
+    var animation = new Animation(document.body, [], { duration: 1000 });
+
+    // TODO: access internal _timing for now, until .timing is properly generated
+    var timing = animation._timing;
+
+    assert.equal(timing.duration, 1000);
+    assert.equal(timing.iterations, 1.0);
+
+    var player = document.timeline.play(animation);
+    tick(50);
+    assert.equal(player.currentTime, 0);
+
+    tick(350);
+    assert.equal(player.currentTime, 300);
+
+    timing.iterations = 0.5;
+    animation.timing.iterations = 0.5;
+    tick(850);
+    assert.equal(player.currentTime, 500);
+  });
+
+  test('immediate pause and play later', function() {
+    var animation = new Animation(document.body, [], { duration: 1000 });
+    var player = document.timeline.play(animation);
+    player.pause();
+
+    tick(50);
+    assert(!player.currentTime);
+    assert(!player.startTime);
+
+    tick(150);
+    assert(!player.currentTime);
+    assert(!player.startTime);
+
+    player.play();
+
+    tick(250);
+    assert.equal(player.currentTime, 100);
+    assert.equal(player.startTime, 150);
+  });
+
+  test('composing playbackRate', function() {
+    var target = document.createElement('div');
+    target.style.position = 'absolute';
+    document.body.appendChild(target);
+
+    var timing = { duration: 1000, playbackRate: 0.5 };
+    var animation = new Animation(target, [
+      { left: '0px' },
+      { left: '1000px' }
+    ], timing);
+
+    // 0.5 * 2.0 == 1, so offsetLeft==currentTime
+    var group = new AnimationGroup([animation], { playbackRate: 2.0 });
+    var player = document.timeline.play(animation);
+
+    tick(50);
+    assert.equal(player.startTime, 50);
+
+    tick(150);
+    assert.equal(player.currentTime, 100);
+    assert.equal(target.offsetLeft, 100);
+  });
+
+  test('player playbackRate', function() {
+    var target = document.createElement('div');
+    target.style.position = 'absolute';
+    document.body.appendChild(target);
+
+    var timing = { duration: 1000, playbackRate: 0.5 };
+    var animation = new Animation(target, [
+      { left: '0px' },
+      { left: '1000px' }
+    ], timing);
+
+    var player = document.timeline.play(animation);
+
+    // 0.5 * 2.0 == 1, so offsetLeft==currentTime
+    player.playbackRate = 2.0;
+
+    tick(50);
+    assert.equal(player.startTime, 50);
+
+    tick(150);
+    assert.equal(player.currentTime, 100);
+    assert.equal(target.offsetLeft, 100);
+  });
+
   test('pause and scrub', function() {
-    var player = document.body.animate([], { duration: 1000 });
+    // note that this functions natively. However, note that AnimationGroup
+    // is not native on M41, so it still fails there.
+    var animation = new Animation(document.body, [], { duration: 1000 });
+    var player = document.timeline.play(animation);
+    player.pause();
+
+    player.currentTime = 500;
+    assert.equal(player.currentTime, 500);
+  });
+
+  test('pause and scrub group', function() {
+    // note that this functions natively. However, note that AnimationGroup
+    // is not native on M41, so it still fails there.
+    var animation = new Animation(document.body, [], { duration: 1000 });
+    var group = new AnimationGroup([animation]);
+    var player = document.timeline.play(group);
     player.pause();
 
     player.currentTime = 500;