diff --git a/core/api/current.txt b/core/api/current.txt
index d26eb3c79d4d5..ea3f50ae90d8b 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -40884,6 +40884,7 @@ package android.telephony {
   }
 
   public static final class CarrierConfigManager.Apn {
+    field @Deprecated public static final String KEY_PREFIX = "apn.";
     field public static final String KEY_SETTINGS_DEFAULT_PROTOCOL_STRING = "apn.settings_default_protocol_string";
     field public static final String KEY_SETTINGS_DEFAULT_ROAMING_PROTOCOL_STRING = "apn.settings_default_roaming_protocol_string";
     field public static final String PROTOCOL_IPV4 = "IP";
diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index 3d43d031868da..4b57fcbf0ad32 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -1717,8 +1717,14 @@ public class CarrierConfigManager {
      * Configs used for APN setup.
      */
     public static final class Apn {
-        /** Prefix of all Apn.KEY_* constants. */
-        private static final String KEY_PREFIX = "apn.";
+        /**
+         * Prefix of all Apn.KEY_* constants.
+         *
+         * @deprecated Since KEY_PREFIX is unnecessary to public, it will modify to private
+         * next android generation.
+         */
+        @Deprecated
+        public static final String KEY_PREFIX = "apn.";
 
         /** IPv4 internet protocol */
         public static final String PROTOCOL_IPV4 = "IP";