diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index 97b81184b1c32..d0a4aa6ad8e1d 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -1869,7 +1869,7 @@ public class CarrierConfigManager {
         sDefaults.putBoolean(KEY_CARRIER_FORCE_DISABLE_ETWS_CMAS_TEST_BOOL, false);
         sDefaults.putBoolean(KEY_CARRIER_VOLTE_PROVISIONING_REQUIRED_BOOL, false);
         sDefaults.putBoolean(KEY_CARRIER_VOLTE_OVERRIDE_WFC_PROVISIONING_BOOL, false);
-        sDefaults.putBoolean(KEY_CARRIER_VOLTE_TTY_SUPPORTED_BOOL, true);
+        sDefaults.putBoolean(KEY_CARRIER_VOLTE_TTY_SUPPORTED_BOOL, false);
         sDefaults.putBoolean(KEY_CARRIER_ALLOW_TURNOFF_IMS_BOOL, true);
         sDefaults.putBoolean(KEY_CARRIER_IMS_GBA_REQUIRED_BOOL, false);
         sDefaults.putBoolean(KEY_CARRIER_INSTANT_LETTERING_AVAILABLE_BOOL, false);