diff --git a/api/system-current.txt b/api/system-current.txt
index adf9e39ba7cb5..e6a3e9bf3e8e0 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -3639,7 +3639,7 @@ package android.media {
   public final class MediaRecorder.AudioSource {
     field @RequiresPermission(android.Manifest.permission.CAPTURE_AUDIO_OUTPUT) public static final int ECHO_REFERENCE = 1997; // 0x7cd
     field @RequiresPermission(android.Manifest.permission.CAPTURE_AUDIO_HOTWORD) public static final int HOTWORD = 1999; // 0x7cf
-    field public static final int RADIO_TUNER = 1998; // 0x7ce
+    field @RequiresPermission(android.Manifest.permission.CAPTURE_AUDIO_OUTPUT) public static final int RADIO_TUNER = 1998; // 0x7ce
   }
 
   public class PlayerProxy {
diff --git a/media/java/android/media/MediaRecorder.java b/media/java/android/media/MediaRecorder.java
index bf7da23323a15..9723652b5bd3e 100644
--- a/media/java/android/media/MediaRecorder.java
+++ b/media/java/android/media/MediaRecorder.java
@@ -337,9 +337,14 @@ public class MediaRecorder implements AudioRouting,
 
         /**
          * Audio source for capturing broadcast radio tuner output.
+         * Capturing the radio tuner output requires the
+         * {@link android.Manifest.permission#CAPTURE_AUDIO_OUTPUT} permission.
+         * This permission is reserved for use by system components and is not available to
+         * third-party applications.
          * @hide
          */
         @SystemApi
+        @RequiresPermission(android.Manifest.permission.CAPTURE_AUDIO_OUTPUT)
         public static final int RADIO_TUNER = 1998;
 
         /**