diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index bb15da7b496ce..2dbd1c0ce6749 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -1049,6 +1049,9 @@ public class CarrierConfigManager {
      *
      * When {@code false}, the old behavior is used, where the toggle in accessibility settings is
      * used to set the IMS stack's RTT enabled state.
+     *
+     * @deprecated -- this flag no longer does anything. Remove once the new behavior is verified.
+     *
      * @hide
      */
     public static final String KEY_IGNORE_RTT_MODE_SETTING_BOOL =
@@ -3526,7 +3529,7 @@ public class CarrierConfigManager {
         sDefaults.putInt(KEY_IMS_DTMF_TONE_DELAY_INT, 0);
         sDefaults.putInt(KEY_CDMA_DTMF_TONE_DELAY_INT, 100);
         sDefaults.putBoolean(KEY_CALL_FORWARDING_MAP_NON_NUMBER_TO_VOICEMAIL_BOOL, false);
-        sDefaults.putBoolean(KEY_IGNORE_RTT_MODE_SETTING_BOOL, false);
+        sDefaults.putBoolean(KEY_IGNORE_RTT_MODE_SETTING_BOOL, true);
         sDefaults.putInt(KEY_CDMA_3WAYCALL_FLASH_DELAY_INT , 0);
         sDefaults.putBoolean(KEY_SUPPORT_CONFERENCE_CALL_BOOL, true);
         sDefaults.putBoolean(KEY_SUPPORT_IMS_CONFERENCE_CALL_BOOL, true);