diff --git a/library/core/src/main/java/com/google/android/exoplayer2/metadata/emsg/EventMessage.java b/library/core/src/main/java/com/google/android/exoplayer2/metadata/emsg/EventMessage.java
index 6e0b0b40f2..7e3862ca31 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/metadata/emsg/EventMessage.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/metadata/emsg/EventMessage.java
@@ -27,13 +27,20 @@ import com.google.android.exoplayer2.util.MimeTypes;
import com.google.android.exoplayer2.util.Util;
import java.util.Arrays;
-/**
- * An Event Message (emsg) as defined in ISO 23009-1.
- */
+/** An Event Message (emsg) as defined in ISO 23009-1. */
public final class EventMessage implements Metadata.Entry {
- @VisibleForTesting
- public static final String ID3_SCHEME_ID = "https://developer.apple.com/streaming/emsg-id3";
+ /**
+ * emsg scheme_id_uri from the CMAF
+ * spec.
+ */
+ @VisibleForTesting public static final String ID3_SCHEME_ID_AOM = "https://aomedia.org/emsg/ID3";
+
+ /**
+ * The Apple-hosted scheme_id equivalent to {@code ID3_SCHEME_ID_AOM} - used before AOM adoption.
+ */
+ private static final String ID3_SCHEME_ID_APPLE =
+ "https://developer.apple.com/streaming/emsg-id3";
/**
* scheme_id_uri from section 7.3.2 of