diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index 4a04cf1544061..e675c6df166e2 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -351,6 +351,14 @@ public class CarrierConfigManager {
     public static final String KEY_CI_ACTION_ON_SYS_UPDATE_EXTRA_VAL_STRING =
             "ci_action_on_sys_update_extra_val_string";
 
+    /**
+     * Specifies the amount of gap to be added in millis between DTMF tones. When a non-zero value
+     * is specified, the UE shall wait for the specified amount of time before it sends out
+     * successive DTMF tones on the network.
+     * @hide
+     */
+    public static final String KEY_GSM_DTMF_TONE_DELAY_INT = "gsm_dtmf_tone_delay_int";
+
     /**
      * Specifies the amount of gap to be added in millis between DTMF tones. When a non-zero value
      * is specified, the UE shall wait for the specified amount of time before it sends out
@@ -492,6 +500,7 @@ public class CarrierConfigManager {
         sDefaults.putStringArray(KEY_CDMA_ROAMING_NETWORKS_STRING_ARRAY, null);
         sDefaults.putStringArray(KEY_CDMA_NONROAMING_NETWORKS_STRING_ARRAY, null);
         sDefaults.putBoolean(KEY_FORCE_HOME_NETWORK_BOOL, false);
+        sDefaults.putInt(KEY_GSM_DTMF_TONE_DELAY_INT, 0);
         sDefaults.putInt(KEY_IMS_DTMF_TONE_DELAY_INT, 0);
         sDefaults.putBoolean(KEY_SUPPORT_CONFERENCE_CALL_BOOL, true);
         sDefaults.putBoolean(KEY_EDITABLE_ENHANCED_4G_LTE_BOOL, true);