diff --git a/library/src/androidTest/java/com/google/android/exoplayer2/ExoPlayerTest.java b/library/src/androidTest/java/com/google/android/exoplayer2/ExoPlayerTest.java
index 211ae954b2..0f6f3b07b1 100644
--- a/library/src/androidTest/java/com/google/android/exoplayer2/ExoPlayerTest.java
+++ b/library/src/androidTest/java/com/google/android/exoplayer2/ExoPlayerTest.java
@@ -84,7 +84,6 @@ public final class ExoPlayerTest extends TestCase {
     private Format expectedFormat;
     private ExoPlayer player;
     private Exception exception;
-    private boolean seenPositionDiscontinuity;
 
     public PlayerWrapper() {
       endedCountDownLatch = new CountDownLatch(1);
@@ -121,7 +120,7 @@ public final class ExoPlayerTest extends TestCase {
             player.setPlayWhenReady(true);
             player.prepare(new FakeMediaSource(timeline, manifest, format));
           } catch (Exception e) {
-            handlePlayerException(e);
+            handleError(e);
           }
         }
       });
@@ -136,7 +135,7 @@ public final class ExoPlayerTest extends TestCase {
               player.release();
             }
           } catch (Exception e) {
-            handlePlayerException(e);
+            handleError(e);
           } finally {
             playerThread.quit();
           }
@@ -145,7 +144,7 @@ public final class ExoPlayerTest extends TestCase {
       playerThread.join();
     }
 
-    private void handlePlayerException(Exception exception) {
+    private void handleError(Exception exception) {
       if (this.exception == null) {
         this.exception = exception;
       }
@@ -180,20 +179,13 @@ public final class ExoPlayerTest extends TestCase {
 
     @Override
     public void onPlayerError(ExoPlaybackException exception) {
-      this.exception = exception;
-      endedCountDownLatch.countDown();
+      handleError(exception);
     }
 
     @Override
     public void onPositionDiscontinuity() {
-      assertFalse(seenPositionDiscontinuity);
-      assertEquals(0, player.getCurrentWindowIndex());
-      assertEquals(0, player.getCurrentPeriodIndex());
-      assertEquals(0, player.getCurrentPosition());
-      assertEquals(0, player.getBufferedPosition());
-      assertEquals(expectedTimeline, player.getCurrentTimeline());
-      assertEquals(expectedManifest, player.getCurrentManifest());
-      seenPositionDiscontinuity = true;
+      // Should never happen.
+      handleError(new IllegalStateException("Received position discontinuity"));
     }
 
   }
diff --git a/library/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java b/library/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java
index a7cbeb524c..ab4e59e08f 100644
--- a/library/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java
+++ b/library/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java
@@ -332,8 +332,10 @@ import java.util.concurrent.CopyOnWriteArraySet;
       case ExoPlayerImplInternal.MSG_SEEK_ACK: {
         if (--pendingSeekAcks == 0) {
           playbackInfo = (ExoPlayerImplInternal.PlaybackInfo) msg.obj;
-          for (EventListener listener : listeners) {
-            listener.onPositionDiscontinuity();
+          if (msg.arg1 != 0) {
+            for (EventListener listener : listeners) {
+              listener.onPositionDiscontinuity();
+            }
           }
         }
         break;
diff --git a/library/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java b/library/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java
index 8866bb7c48..afae56f1aa 100644
--- a/library/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java
+++ b/library/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java
@@ -559,7 +559,7 @@ import java.io.IOException;
       // The seek position was valid for the timeline that it was performed into, but the
       // timeline has changed and a suitable seek position could not be resolved in the new one.
       playbackInfo = new PlaybackInfo(0, 0);
-      eventHandler.obtainMessage(MSG_SEEK_ACK, playbackInfo).sendToTarget();
+      eventHandler.obtainMessage(MSG_SEEK_ACK, 1, 0, playbackInfo).sendToTarget();
       // Set the internal position to (0,TIME_UNSET) so that a subsequent seek to (0,0) isn't
       // ignored.
       playbackInfo = new PlaybackInfo(0, C.TIME_UNSET);
@@ -569,6 +569,7 @@ import java.io.IOException;
       return;
     }
 
+    boolean seekPositionAdjusted = seekPosition.windowPositionUs == C.TIME_UNSET;
     int periodIndex = periodPosition.first;
     long periodPositionUs = periodPosition.second;
 
@@ -578,10 +579,13 @@ import java.io.IOException;
         // Seek position equals the current position. Do nothing.
         return;
       }
-      periodPositionUs = seekToPeriodPosition(periodIndex, periodPositionUs);
+      long newPeriodPositionUs = seekToPeriodPosition(periodIndex, periodPositionUs);
+      seekPositionAdjusted |= periodPositionUs != newPeriodPositionUs;
+      periodPositionUs = newPeriodPositionUs;
     } finally {
       playbackInfo = new PlaybackInfo(periodIndex, periodPositionUs);
-      eventHandler.obtainMessage(MSG_SEEK_ACK, playbackInfo).sendToTarget();
+      eventHandler.obtainMessage(MSG_SEEK_ACK, seekPositionAdjusted ? 1 : 0, 0, playbackInfo)
+          .sendToTarget();
     }
   }