diff --git a/java/com/android/dialer/telecom/TelecomUtil.java b/java/com/android/dialer/telecom/TelecomUtil.java
index f05ec20..2608cb2 100644
--- a/java/com/android/dialer/telecom/TelecomUtil.java
+++ b/java/com/android/dialer/telecom/TelecomUtil.java
@@ -26,7 +26,6 @@
 import android.os.Build.VERSION;
 import android.os.Build.VERSION_CODES;
 import android.provider.CallLog.Calls;
-import android.provider.Settings;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.annotation.RequiresPermission;
@@ -300,11 +299,6 @@
     return instance.isDefaultDialer(context);
   }
 
-  public static boolean isRttEnabled(Context context) {
-    return Settings.System.getInt(context.getContentResolver(), Settings.System.RTT_CALLING_MODE, 0)
-        != 0;
-  }
-
   /** @return the other SIM based PhoneAccountHandle that is not {@code currentAccount} */
   @Nullable
   @RequiresPermission(permission.READ_PHONE_STATE)
diff --git a/java/com/android/incallui/CallButtonPresenter.java b/java/com/android/incallui/CallButtonPresenter.java
index 38c8da8..8334603 100644
--- a/java/com/android/incallui/CallButtonPresenter.java
+++ b/java/com/android/incallui/CallButtonPresenter.java
@@ -479,7 +479,7 @@
             // Most devices cannot make calls on 2 SIMs at the same time.
             && InCallPresenter.getInstance().getCallList().getAllCalls().size() == 1;
 
-    boolean showUpgradeToRtt = TelecomUtil.isRttEnabled(context) && call.canUpgradeToRttCall();
+    boolean showUpgradeToRtt = call.canUpgradeToRttCall();
 
     inCallButtonUi.showButton(InCallButtonIds.BUTTON_AUDIO, true);
     inCallButtonUi.showButton(InCallButtonIds.BUTTON_SWAP, showSwap);