diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 3e867cf102..0232b429ab 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -15,6 +15,8 @@
 *   Track selection:
     *   Flatten `TrackSelectionOverrides` class into `TrackSelectionParameters`,
         and promote `TrackSelectionOverride` to a top level class.
+*   Audio:
+    *   Use LG AC3 audio decoder advertising non-standard MIME type.
 *   Extractors:
     *   Matroska: Parse `DiscardPadding` for Opus tracks.
 *   UI:
diff --git a/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/mediacodec/MediaCodecUtil.java b/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/mediacodec/MediaCodecUtil.java
index ca24d21b20..c3200150d0 100644
--- a/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/mediacodec/MediaCodecUtil.java
+++ b/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/mediacodec/MediaCodecUtil.java
@@ -443,6 +443,8 @@ public final class MediaCodecUtil {
       return "audio/x-lg-alac";
     } else if (mimeType.equals(MimeTypes.AUDIO_FLAC) && "OMX.lge.flac.decoder".equals(name)) {
       return "audio/x-lg-flac";
+    } else if (mimeType.equals(MimeTypes.AUDIO_AC3) && "OMX.lge.ac3.decoder".equals(name)) {
+      return "audio/lg-ac3";
     }
 
     return null;