diff --git a/audio/common/4.0/types.hal b/audio/common/4.0/types.hal
index 4efdea3fa4..0adff734d3 100644
--- a/audio/common/4.0/types.hal
+++ b/audio/common/4.0/types.hal
@@ -104,8 +104,6 @@ enum AudioStreamType : int32_t {
     TTS              = 9,  // Transmitted Through Speaker.  Plays over speaker
                            // only, silent on other devices
     ACCESSIBILITY    = 10, // For accessibility talk back prompts
-    REROUTING        = 11, // For dynamic policy output mixes
-    PATCH            = 12, // For internal audio flinger tracks.  Fixed volume
 };
 
 @export(name="audio_source_t", value_prefix="AUDIO_SOURCE_")
@@ -657,6 +655,8 @@ enum AudioUsage : int32_t {
 /** Type of audio generated by an application. */
 @export(name="audio_content_type_t", value_prefix="AUDIO_CONTENT_TYPE_")
 enum AudioContentType : uint32_t {
+    // Do not change these values without updating their counterparts
+    // in frameworks/base/media/java/android/media/AudioAttributes.java
     UNKNOWN      = 0,
     SPEECH       = 1,
     MUSIC        = 2,