diff --git a/src/com/android/services/telephony/DisconnectCauseUtil.java b/src/com/android/services/telephony/DisconnectCauseUtil.java
index 235c4b9..d7db345 100644
--- a/src/com/android/services/telephony/DisconnectCauseUtil.java
+++ b/src/com/android/services/telephony/DisconnectCauseUtil.java
@@ -92,6 +92,7 @@
             case android.telephony.DisconnectCause.EMERGENCY_ONLY:
             case android.telephony.DisconnectCause.FDN_BLOCKED:
             case android.telephony.DisconnectCause.LIMIT_EXCEEDED:
+            case android.telephony.DisconnectCause.VIDEO_CALL_NOT_ALLOWED_WHILE_TTY_ENABLED:
                 return DisconnectCause.RESTRICTED;
 
             case android.telephony.DisconnectCause.CDMA_ACCESS_FAILURE:
@@ -324,6 +325,10 @@
                 resourceId = R.string.incall_error_missing_voicemail_number;
                 break;
 
+            case android.telephony.DisconnectCause.VIDEO_CALL_NOT_ALLOWED_WHILE_TTY_ENABLED:
+                resourceId = R.string.callFailed_video_call_tty_enabled;
+                break;
+
             case android.telephony.DisconnectCause.OUTGOING_CANCELED:
                 // We don't want to show any dialog for the canceled case since the call was
                 // either canceled by the user explicitly (end-call button pushed immediately)
@@ -371,6 +376,7 @@
             case android.telephony.DisconnectCause.ERROR_UNSPECIFIED:
             case android.telephony.DisconnectCause.LOCAL:
             case android.telephony.DisconnectCause.NORMAL:
+            case android.telephony.DisconnectCause.VIDEO_CALL_NOT_ALLOWED_WHILE_TTY_ENABLED:
                 return ToneGenerator.TONE_PROP_PROMPT;
 
             case android.telephony.DisconnectCause.IMS_MERGED_SUCCESSFULLY:
diff --git a/src/com/android/services/telephony/TelephonyConnectionService.java b/src/com/android/services/telephony/TelephonyConnectionService.java
index 5f68d9a..c919059 100644
--- a/src/com/android/services/telephony/TelephonyConnectionService.java
+++ b/src/com/android/services/telephony/TelephonyConnectionService.java
@@ -26,6 +26,8 @@
 import android.telecom.ConnectionService;
 import android.telecom.PhoneAccount;
 import android.telecom.PhoneAccountHandle;
+import android.telecom.TelecomManager;
+import android.telecom.VideoProfile;
 import android.telephony.CarrierConfigManager;
 import android.telephony.DisconnectCause;
 import android.telephony.PhoneNumberUtils;
@@ -275,6 +277,14 @@
             }
         }
 
+        final Context context = getApplicationContext();
+        if (VideoProfile.isVideo(request.getVideoState()) && isTtyModeEnabled(context) &&
+                !isEmergencyNumber) {
+            return Connection.createFailedConnection(
+                    DisconnectCauseUtil.toTelecomDisconnectCause(
+                            DisconnectCause.VIDEO_CALL_NOT_ALLOWED_WHILE_TTY_ENABLED));
+        }
+
         final TelephonyConnection connection =
                 createConnectionFor(phone, null, true /* isOutgoing */, request.getAccountHandle(),
                         request.getTelecomCallId());
@@ -623,4 +633,11 @@
             mImsConferenceController.remove(connection);
         }
     }
+
+    private boolean isTtyModeEnabled(Context context) {
+        return (android.provider.Settings.Secure.getInt(
+                context.getContentResolver(),
+                android.provider.Settings.Secure.PREFERRED_TTY_MODE,
+                TelecomManager.TTY_MODE_OFF) != TelecomManager.TTY_MODE_OFF);
+    }
 }