diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 2263131204e..434f4f2c744 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -65,6 +65,8 @@
 * Publish `testutils` module to simplify unit testing with ExoPlayer
   ([#6267](https://github.com/google/ExoPlayer/issues/6267)).
 * Add `uid` to `Timeline.Window` to uniquely identify window instances.
+* Fix decoder selection for E-AC3 JOC streams
+  ([#6398](https://github.com/google/ExoPlayer/issues/6398)).
 
 ### 2.10.4 ###
 
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/audio/MediaCodecAudioRenderer.java b/library/core/src/main/java/com/google/android/exoplayer2/audio/MediaCodecAudioRenderer.java
index 251901f4f26..34f8363c78b 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/audio/MediaCodecAudioRenderer.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/audio/MediaCodecAudioRenderer.java
@@ -46,6 +46,7 @@
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
 import java.nio.ByteBuffer;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
@@ -361,10 +362,11 @@ protected List<MediaCodecInfo> getDecoderInfos(
     decoderInfos = MediaCodecUtil.getDecoderInfosSortedByFormatSupport(decoderInfos, format);
     if (MimeTypes.AUDIO_E_AC3_JOC.equals(format.sampleMimeType)) {
       // E-AC3 decoders can decode JOC streams, but in 2-D rather than 3-D.
-      List<MediaCodecInfo> eac3DecoderInfos =
+      List<MediaCodecInfo> decoderInfosWithEac3 = new ArrayList<>(decoderInfos);
+      decoderInfosWithEac3.addAll(
           mediaCodecSelector.getDecoderInfos(
-              MimeTypes.AUDIO_E_AC3, requiresSecureDecoder, /* requiresTunnelingDecoder= */ false);
-      decoderInfos.addAll(eac3DecoderInfos);
+              MimeTypes.AUDIO_E_AC3, requiresSecureDecoder, /* requiresTunnelingDecoder= */ false));
+      decoderInfos = decoderInfosWithEac3;
     }
     return Collections.unmodifiableList(decoderInfos);
   }
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecSelector.java b/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecSelector.java
index a639cf9a1bd..10ff81147ea 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecSelector.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecSelector.java
@@ -52,7 +52,8 @@ public MediaCodecInfo getPassthroughDecoderInfo() throws DecoderQueryException {
    * @param mimeType The MIME type for which a decoder is required.
    * @param requiresSecureDecoder Whether a secure decoder is required.
    * @param requiresTunnelingDecoder Whether a tunneling decoder is required.
-   * @return A list of {@link MediaCodecInfo}s corresponding to decoders. May be empty.
+   * @return An unmodifiable list of {@link MediaCodecInfo}s corresponding to decoders. May be
+   *     empty.
    * @throws DecoderQueryException Thrown if there was an error querying decoders.
    */
   List<MediaCodecInfo> getDecoderInfos(
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecUtil.java b/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecUtil.java
index eb97d546e5a..1293f14d08f 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecUtil.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecUtil.java
@@ -156,8 +156,8 @@ public static MediaCodecInfo getDecoderInfo(String mimeType, boolean secure, boo
    *     unless secure decryption really is required.
    * @param tunneling Whether the decoder is required to support tunneling. Always pass false unless
    *     tunneling really is required.
-   * @return A list of all {@link MediaCodecInfo}s for the given mime type, in the order given by
-   *     {@link MediaCodecList}.
+   * @return An unmodifiable list of all {@link MediaCodecInfo}s for the given mime type, in the
+   *     order given by {@link MediaCodecList}.
    * @throws DecoderQueryException If there was an error querying the available decoders.
    */
   public static synchronized List<MediaCodecInfo> getDecoderInfos(