diff --git a/lib/media/playhead.js b/lib/media/playhead.js
index 59d49edde..b5177d5a7 100644
--- a/lib/media/playhead.js
+++ b/lib/media/playhead.js
@@ -143,10 +143,12 @@ shaka.media.Playhead.prototype.getStartTime_ = function() {
 
   var startTime;
   if (this.timeline_.getDuration() < Number.POSITIVE_INFINITY) {
+    // If the presentation is VOD, or if the presentation is live but has
+    // finished broadcasting, then start from the beginning.
     startTime = this.timeline_.getSegmentAvailabilityStart();
   } else {
-    // For live presentations, ensure that the startup buffering goal can be
-    // met.
+    // Otherwise, start near the live-edge, but ensure that the startup
+    // buffering goal can be met
     startTime = Math.max(
         this.timeline_.getSegmentAvailabilityEnd() - this.rebufferingGoal_,
         this.timeline_.getSegmentAvailabilityStart());
@@ -277,13 +279,14 @@ shaka.media.Playhead.prototype.onSeeking_ = function() {
  */
 shaka.media.Playhead.prototype.reposition_ = function(currentTime) {
   var availabilityDuration = this.timeline_.getSegmentAvailabilityDuration();
-  var live = (availabilityDuration != null) &&
-             (availabilityDuration < Number.POSITIVE_INFINITY);
-
   var start = this.timeline_.getSegmentAvailabilityStart();
   var end = this.timeline_.getSegmentAvailabilityEnd();
 
-  if (!live) {
+  if (availabilityDuration == null ||
+      availabilityDuration == Number.POSITIVE_INFINITY) {
+    // If the presentation is live but has an infinite segment availability
+    // duration then we can treat it as VOD since the start of the seek range
+    // is not moving.
     if (currentTime < start) {
       shaka.log.v1('Seek before start.');
       return start;
diff --git a/lib/player.js b/lib/player.js
index e0c6edeb9..4815ee96e 100644
--- a/lib/player.js
+++ b/lib/player.js
@@ -634,8 +634,10 @@ shaka.Player.prototype.getNetworkingEngine = function() {
  */
 shaka.Player.prototype.isLive = function() {
   if (!this.manifest_) return false;
+
+  //  If the presentation has a segment availability window then it's live.
   var timeline = this.manifest_.presentationTimeline;
-  return timeline.getDuration() == Number.POSITIVE_INFINITY;
+  return timeline.getSegmentAvailabilityDuration() != null;
 };