diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/MediaPeriod.java b/library/core/src/main/java/com/google/android/exoplayer2/source/MediaPeriod.java
index 8d7bd768bb..997f94bbfe 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/MediaPeriod.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/MediaPeriod.java
@@ -67,7 +67,7 @@ public interface MediaPeriod extends SequenceableLoader {
    * Throws an error that's preventing the period from becoming prepared. Does nothing if no such
    * error exists.
    *
-   * <p>This method should only be called before the period has completed preparation.
+   * <p>This method is only called before the period has completed preparation.
    *
    * @throws IOException The underlying error.
    */
@@ -76,7 +76,7 @@ public interface MediaPeriod extends SequenceableLoader {
   /**
    * Returns the {@link TrackGroup}s exposed by the period.
    *
-   * <p>This method should only be called after the period has been prepared.
+   * <p>This method is only called after the period has been prepared.
    *
    * @return The {@link TrackGroup}s.
    */
@@ -93,7 +93,7 @@ public interface MediaPeriod extends SequenceableLoader {
    * corresponding flag in {@code streamResetFlags} will be set to true. This flag will also be set
    * if a new sample stream is created.
    *
-   * <p>This method should only be called after the period has been prepared.
+   * <p>This method is only called after the period has been prepared.
    *
    * @param selections The renderer track selections.
    * @param mayRetainStreamFlags Flags indicating whether the existing sample stream can be retained
@@ -117,7 +117,7 @@ public interface MediaPeriod extends SequenceableLoader {
   /**
    * Discards buffered media up to the specified position.
    *
-   * <p>This method should only be called after the period has been prepared.
+   * <p>This method is only called after the period has been prepared.
    *
    * @param positionUs The position in microseconds.
    * @param toKeyframe If true then for each track discards samples up to the keyframe before or at
@@ -131,8 +131,8 @@ public interface MediaPeriod extends SequenceableLoader {
    * <p>After this method has returned a value other than {@link C#TIME_UNSET}, all {@link
    * SampleStream}s provided by the period are guaranteed to start from a key frame.
    *
-   * <p>This method should only be called after the period has been prepared. It must be called
-   * before attempting to read from any {@link SampleStream}s provided by the period.
+   * <p>This method is only called after the period has been prepared and before reading from any
+   * {@link SampleStream}s provided by the period.
    *
    * @return If a discontinuity was read then the playback position in microseconds after the
    *     discontinuity. Else {@link C#TIME_UNSET}.
@@ -145,7 +145,7 @@ public interface MediaPeriod extends SequenceableLoader {
    * <p>After this method has been called, all {@link SampleStream}s provided by the period are
    * guaranteed to start from a key frame.
    *
-   * <p>This method should only be called when at least one track is selected.
+   * <p>This method is only called when at least one track is selected.
    *
    * @param positionUs The seek position in microseconds.
    * @return The actual position to which the period was seeked, in microseconds.
@@ -156,7 +156,7 @@ public interface MediaPeriod extends SequenceableLoader {
    * Returns the position to which a seek will be performed, given the specified seek position and
    * {@link SeekParameters}.
    *
-   * <p>This method should only be called after the period has been prepared.
+   * <p>This method is only called after the period has been prepared.
    *
    * @param positionUs The seek position in microseconds.
    * @param seekParameters Parameters that control how the seek is performed. Implementations may
@@ -170,7 +170,7 @@ public interface MediaPeriod extends SequenceableLoader {
   /**
    * Returns an estimate of the position up to which data is buffered for the enabled tracks.
    *
-   * <p>This method should only be called when at least one track is selected.
+   * <p>This method is only called when at least one track is selected.
    *
    * @return An estimate of the absolute position in microseconds up to which data is buffered, or
    *     {@link C#TIME_END_OF_SOURCE} if the track is fully buffered.
@@ -181,8 +181,8 @@ public interface MediaPeriod extends SequenceableLoader {
   /**
    * Returns the next load time, or {@link C#TIME_END_OF_SOURCE} if loading has finished.
    *
-   * <p>This method should only be called after the period has been prepared. It may be called when
-   * no tracks are selected.
+   * <p>This method is only called after the period has been prepared. It may be called when no
+   * tracks are selected.
    */
   @Override
   long getNextLoadPositionUs();
@@ -209,7 +209,7 @@ public interface MediaPeriod extends SequenceableLoader {
   /**
    * Re-evaluates the buffer given the playback position.
    *
-   * <p>This method should only be called after the period has been prepared.
+   * <p>This method is only called after the period has been prepared.
    *
    * <p>A period may choose to discard buffered media so that it can be re-buffered in a different
    * quality.
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/MergingMediaPeriod.java b/library/core/src/main/java/com/google/android/exoplayer2/source/MergingMediaPeriod.java
index d8b64fff7e..a4fc8c6b00 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/MergingMediaPeriod.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/MergingMediaPeriod.java
@@ -21,6 +21,7 @@ import com.google.android.exoplayer2.trackselection.TrackSelection;
 import com.google.android.exoplayer2.util.Assertions;
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.IdentityHashMap;
 
 /**
@@ -32,9 +33,9 @@ import java.util.IdentityHashMap;
 
   private final IdentityHashMap<SampleStream, Integer> streamPeriodIndices;
   private final CompositeSequenceableLoaderFactory compositeSequenceableLoaderFactory;
+  private final ArrayList<MediaPeriod> childrenPendingPreparation;
 
   private Callback callback;
-  private int pendingChildPrepareCount;
   private TrackGroupArray trackGroups;
 
   private MediaPeriod[] enabledPeriods;
@@ -44,13 +45,16 @@ import java.util.IdentityHashMap;
       MediaPeriod... periods) {
     this.compositeSequenceableLoaderFactory = compositeSequenceableLoaderFactory;
     this.periods = periods;
+    childrenPendingPreparation = new ArrayList<>();
+    compositeSequenceableLoader =
+        compositeSequenceableLoaderFactory.createCompositeSequenceableLoader();
     streamPeriodIndices = new IdentityHashMap<>();
   }
 
   @Override
   public void prepare(Callback callback, long positionUs) {
     this.callback = callback;
-    pendingChildPrepareCount = periods.length;
+    Collections.addAll(childrenPendingPreparation, periods);
     for (MediaPeriod period : periods) {
       period.prepare(this, positionUs);
     }
@@ -147,7 +151,16 @@ import java.util.IdentityHashMap;
 
   @Override
   public boolean continueLoading(long positionUs) {
-    return compositeSequenceableLoader.continueLoading(positionUs);
+    if (!childrenPendingPreparation.isEmpty()) {
+      // Preparation is still going on.
+      int childrenPendingPreparationSize = childrenPendingPreparation.size();
+      for (int i = 0; i < childrenPendingPreparationSize; i++) {
+        childrenPendingPreparation.get(i).continueLoading(positionUs);
+      }
+      return false;
+    } else {
+      return compositeSequenceableLoader.continueLoading(positionUs);
+    }
   }
 
   @Override
@@ -201,8 +214,9 @@ import java.util.IdentityHashMap;
   // MediaPeriod.Callback implementation
 
   @Override
-  public void onPrepared(MediaPeriod ignored) {
-    if (--pendingChildPrepareCount > 0) {
+  public void onPrepared(MediaPeriod preparedPeriod) {
+    childrenPendingPreparation.remove(preparedPeriod);
+    if (!childrenPendingPreparation.isEmpty()) {
       return;
     }
     int totalTrackGroupCount = 0;
@@ -224,10 +238,6 @@ import java.util.IdentityHashMap;
 
   @Override
   public void onContinueLoadingRequested(MediaPeriod ignored) {
-    if (trackGroups == null) {
-      // Still preparing.
-      return;
-    }
     callback.onContinueLoadingRequested(this);
   }
 
diff --git a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaPeriod.java b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaPeriod.java
index 8076fd8359..01b042e7a5 100644
--- a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaPeriod.java
+++ b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaPeriod.java
@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.source.hls;
 
-import android.os.Handler;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.SeekParameters;
@@ -55,7 +54,6 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
   private final Allocator allocator;
   private final IdentityHashMap<SampleStream, Integer> streamWrapperIndices;
   private final TimestampAdjusterProvider timestampAdjusterProvider;
-  private final Handler continueLoadingHandler;
   private final CompositeSequenceableLoaderFactory compositeSequenceableLoaderFactory;
   private final boolean allowChunklessPreparation;
 
@@ -84,9 +82,10 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
     this.allocator = allocator;
     this.compositeSequenceableLoaderFactory = compositeSequenceableLoaderFactory;
     this.allowChunklessPreparation = allowChunklessPreparation;
+    compositeSequenceableLoader =
+        compositeSequenceableLoaderFactory.createCompositeSequenceableLoader();
     streamWrapperIndices = new IdentityHashMap<>();
     timestampAdjusterProvider = new TimestampAdjusterProvider();
-    continueLoadingHandler = new Handler();
     sampleStreamWrappers = new HlsSampleStreamWrapper[0];
     enabledSampleStreamWrappers = new HlsSampleStreamWrapper[0];
     eventDispatcher.mediaPeriodCreated();
@@ -94,7 +93,6 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
 
   public void release() {
     playlistTracker.removeListener(this);
-    continueLoadingHandler.removeCallbacksAndMessages(null);
     for (HlsSampleStreamWrapper sampleStreamWrapper : sampleStreamWrappers) {
       sampleStreamWrapper.release();
     }
@@ -214,7 +212,15 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
 
   @Override
   public boolean continueLoading(long positionUs) {
-    return compositeSequenceableLoader.continueLoading(positionUs);
+    if (trackGroups == null) {
+      // Preparation is still going on.
+      for (HlsSampleStreamWrapper wrapper : sampleStreamWrappers) {
+        wrapper.continuePreparing();
+      }
+      return false;
+    } else {
+      return compositeSequenceableLoader.continueLoading(positionUs);
+    }
   }
 
   @Override
@@ -288,10 +294,6 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
 
   @Override
   public void onContinueLoadingRequested(HlsSampleStreamWrapper sampleStreamWrapper) {
-    if (trackGroups == null) {
-      // Still preparing.
-      return;
-    }
     callback.onContinueLoadingRequested(this);
   }
 
@@ -299,7 +301,7 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
 
   @Override
   public void onPlaylistChanged() {
-    continuePreparingOrLoading();
+    callback.onContinueLoadingRequested(this);
   }
 
   @Override
@@ -307,7 +309,7 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
     for (HlsSampleStreamWrapper streamWrapper : sampleStreamWrappers) {
       streamWrapper.onPlaylistBlacklisted(url, blacklistMs);
     }
-    continuePreparingOrLoading();
+    callback.onContinueLoadingRequested(this);
   }
 
   // Internal methods.
@@ -475,17 +477,6 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
         muxedAudioFormat, minLoadableRetryCount, eventDispatcher);
   }
 
-  private void continuePreparingOrLoading() {
-    if (trackGroups != null) {
-      callback.onContinueLoadingRequested(this);
-    } else {
-      // Some of the wrappers were waiting for their media playlist to prepare.
-      for (HlsSampleStreamWrapper wrapper : sampleStreamWrappers) {
-        wrapper.continuePreparing();
-      }
-    }
-  }
-
   private static Format deriveVideoFormat(Format variantFormat) {
     String codecs = Util.getCodecsOfType(variantFormat.codecs, C.TRACK_TYPE_VIDEO);
     String mimeType = MimeTypes.getMediaMimeType(codecs);
diff --git a/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeMediaPeriod.java b/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeMediaPeriod.java
index 40d9b1ef9f..a251bd5ef0 100644
--- a/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeMediaPeriod.java
+++ b/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeMediaPeriod.java
@@ -219,7 +219,6 @@ public class FakeMediaPeriod implements MediaPeriod {
 
   @Override
   public boolean continueLoading(long positionUs) {
-    assertThat(prepared).isTrue();
     return false;
   }