diff --git a/InCallUI/src/com/android/incallui/AudioModeProvider.java b/InCallUI/src/com/android/incallui/AudioModeProvider.java
index e7ffecc..961fb11 100644
--- a/InCallUI/src/com/android/incallui/AudioModeProvider.java
+++ b/InCallUI/src/com/android/incallui/AudioModeProvider.java
@@ -16,10 +16,10 @@
 
 package com.android.incallui;
 
-import android.telecom.CallAudioState;
-
 import com.google.common.collect.Lists;
 
+import com.android.dialer.compat.CallAudioStateCompat;
+
 import java.util.List;
 
 /**
@@ -30,19 +30,20 @@
     static final int AUDIO_MODE_INVALID = 0;
 
     private static AudioModeProvider sAudioModeProvider = new AudioModeProvider();
-    private int mAudioMode = CallAudioState.ROUTE_EARPIECE;
+    private int mAudioMode = CallAudioStateCompat.ROUTE_EARPIECE;
     private boolean mMuted = false;
-    private int mSupportedModes = CallAudioState.ROUTE_EARPIECE | CallAudioState.ROUTE_BLUETOOTH |
-        CallAudioState.ROUTE_WIRED_HEADSET | CallAudioState.ROUTE_SPEAKER;
+    private int mSupportedModes = CallAudioStateCompat.ROUTE_EARPIECE
+            | CallAudioStateCompat.ROUTE_BLUETOOTH | CallAudioStateCompat.ROUTE_WIRED_HEADSET
+            | CallAudioStateCompat.ROUTE_SPEAKER;
     private final List<AudioModeListener> mListeners = Lists.newArrayList();
 
     public static AudioModeProvider getInstance() {
         return sAudioModeProvider;
     }
 
-    public void onAudioStateChanged(CallAudioState audioState) {
-        onAudioModeChange(audioState.getRoute(), audioState.isMuted());
-        onSupportedAudioModeChange(audioState.getSupportedRouteMask());
+    public void onAudioStateChanged(boolean isMuted, int route, int supportedRouteMask) {
+        onAudioModeChange(route, isMuted);
+        onSupportedAudioModeChange(supportedRouteMask);
     }
 
     public void onAudioModeChange(int newMode, boolean muted) {
diff --git a/InCallUI/src/com/android/incallui/CallButtonFragment.java b/InCallUI/src/com/android/incallui/CallButtonFragment.java
index 1d32d8f..6538474 100644
--- a/InCallUI/src/com/android/incallui/CallButtonFragment.java
+++ b/InCallUI/src/com/android/incallui/CallButtonFragment.java
@@ -16,18 +16,28 @@
 
 package com.android.incallui;
 
-import static com.android.incallui.CallButtonFragment.Buttons.*;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_ADD_CALL;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_AUDIO;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_COUNT;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_DIALPAD;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_HOLD;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_MANAGE_VIDEO_CONFERENCE;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_MERGE;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_MUTE;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_PAUSE_VIDEO;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_SWAP;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_SWITCH_CAMERA;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_UPGRADE_TO_VIDEO;
 
 import android.content.Context;
 import android.content.res.ColorStateList;
 import android.content.res.Resources;
 import android.graphics.drawable.Drawable;
-import android.graphics.drawable.LayerDrawable;
 import android.graphics.drawable.GradientDrawable;
+import android.graphics.drawable.LayerDrawable;
 import android.graphics.drawable.RippleDrawable;
 import android.graphics.drawable.StateListDrawable;
 import android.os.Bundle;
-import android.telecom.CallAudioState;
 import android.util.SparseIntArray;
 import android.view.ContextThemeWrapper;
 import android.view.HapticFeedbackConstants;
@@ -43,6 +53,7 @@
 import android.widget.PopupMenu.OnMenuItemClickListener;
 
 import com.android.contacts.common.util.MaterialColorMapUtils.MaterialPalette;
+import com.android.dialer.compat.CallAudioStateCompat;
 
 /**
  * Fragment for call control buttons
@@ -516,20 +527,20 @@
         Log.d(this, "  id: " + item.getItemId());
         Log.d(this, "  title: '" + item.getTitle() + "'");
 
-        int mode = CallAudioState.ROUTE_WIRED_OR_EARPIECE;
+        int mode = CallAudioStateCompat.ROUTE_WIRED_OR_EARPIECE;
 
         switch (item.getItemId()) {
             case R.id.audio_mode_speaker:
-                mode = CallAudioState.ROUTE_SPEAKER;
+                mode = CallAudioStateCompat.ROUTE_SPEAKER;
                 break;
             case R.id.audio_mode_earpiece:
             case R.id.audio_mode_wired_headset:
                 // InCallCallAudioState.ROUTE_EARPIECE means either the handset earpiece,
                 // or the wired headset (if connected.)
-                mode = CallAudioState.ROUTE_WIRED_OR_EARPIECE;
+                mode = CallAudioStateCompat.ROUTE_WIRED_OR_EARPIECE;
                 break;
             case R.id.audio_mode_bluetooth:
-                mode = CallAudioState.ROUTE_BLUETOOTH;
+                mode = CallAudioStateCompat.ROUTE_BLUETOOTH;
                 break;
             default:
                 Log.e(this, "onMenuItemClick:  unexpected View ID " + item.getItemId()
@@ -559,9 +570,9 @@
      */
     private void onAudioButtonClicked() {
         Log.d(this, "onAudioButtonClicked: " +
-                CallAudioState.audioRouteToString(getPresenter().getSupportedAudio()));
+                CallAudioStateCompat.audioRouteToString(getPresenter().getSupportedAudio()));
 
-        if (isSupported(CallAudioState.ROUTE_BLUETOOTH)) {
+        if (isSupported(CallAudioStateCompat.ROUTE_BLUETOOTH)) {
             showAudioModePopup();
         } else {
             getPresenter().toggleSpeakerphone();
@@ -596,8 +607,8 @@
      * are visible based on the supported audio formats.
      */
     private void updateAudioButtons(int supportedModes) {
-        final boolean bluetoothSupported = isSupported(CallAudioState.ROUTE_BLUETOOTH);
-        final boolean speakerSupported = isSupported(CallAudioState.ROUTE_SPEAKER);
+        final boolean bluetoothSupported = isSupported(CallAudioStateCompat.ROUTE_BLUETOOTH);
+        final boolean speakerSupported = isSupported(CallAudioStateCompat.ROUTE_SPEAKER);
 
         boolean audioButtonEnabled = false;
         boolean audioButtonChecked = false;
@@ -617,9 +628,9 @@
             showMoreIndicator = true;
 
             // Update desired layers:
-            if (isAudio(CallAudioState.ROUTE_BLUETOOTH)) {
+            if (isAudio(CallAudioStateCompat.ROUTE_BLUETOOTH)) {
                 showBluetoothIcon = true;
-            } else if (isAudio(CallAudioState.ROUTE_SPEAKER)) {
+            } else if (isAudio(CallAudioStateCompat.ROUTE_SPEAKER)) {
                 showSpeakerphoneIcon = true;
             } else {
                 showHandsetIcon = true;
@@ -638,7 +649,7 @@
 
             // The audio button *is* a toggle in this state, and indicated the
             // current state of the speakerphone.
-            audioButtonChecked = isAudio(CallAudioState.ROUTE_SPEAKER);
+            audioButtonChecked = isAudio(CallAudioStateCompat.ROUTE_SPEAKER);
             mAudioButton.setSelected(audioButtonChecked);
 
             // update desired layers:
@@ -699,20 +710,20 @@
 
         // If bluetooth is not supported, the audio buttion will toggle, so use the label "speaker".
         // Otherwise, use the label of the currently selected audio mode.
-        if (!isSupported(CallAudioState.ROUTE_BLUETOOTH)) {
+        if (!isSupported(CallAudioStateCompat.ROUTE_BLUETOOTH)) {
             stringId = R.string.audio_mode_speaker;
         } else {
             switch (mode) {
-                case CallAudioState.ROUTE_EARPIECE:
+                case CallAudioStateCompat.ROUTE_EARPIECE:
                     stringId = R.string.audio_mode_earpiece;
                     break;
-                case CallAudioState.ROUTE_BLUETOOTH:
+                case CallAudioStateCompat.ROUTE_BLUETOOTH:
                     stringId = R.string.audio_mode_bluetooth;
                     break;
-                case CallAudioState.ROUTE_WIRED_HEADSET:
+                case CallAudioStateCompat.ROUTE_WIRED_HEADSET:
                     stringId = R.string.audio_mode_wired_headset;
                     break;
-                case CallAudioState.ROUTE_SPEAKER:
+                case CallAudioStateCompat.ROUTE_SPEAKER:
                     stringId = R.string.audio_mode_speaker;
                     break;
             }
@@ -742,7 +753,7 @@
         // See comments below for the exact logic.
 
         final MenuItem speakerItem = menu.findItem(R.id.audio_mode_speaker);
-        speakerItem.setEnabled(isSupported(CallAudioState.ROUTE_SPEAKER));
+        speakerItem.setEnabled(isSupported(CallAudioStateCompat.ROUTE_SPEAKER));
         // TODO: Show speakerItem as initially "selected" if
         // speaker is on.
 
@@ -751,7 +762,7 @@
         final MenuItem earpieceItem = menu.findItem(R.id.audio_mode_earpiece);
         final MenuItem wiredHeadsetItem = menu.findItem(R.id.audio_mode_wired_headset);
 
-        final boolean usingHeadset = isSupported(CallAudioState.ROUTE_WIRED_HEADSET);
+        final boolean usingHeadset = isSupported(CallAudioStateCompat.ROUTE_WIRED_HEADSET);
         earpieceItem.setVisible(!usingHeadset);
         earpieceItem.setEnabled(!usingHeadset);
         wiredHeadsetItem.setVisible(usingHeadset);
@@ -761,7 +772,7 @@
         // bluetoothIndicatorOn are both false.
 
         final MenuItem bluetoothItem = menu.findItem(R.id.audio_mode_bluetooth);
-        bluetoothItem.setEnabled(isSupported(CallAudioState.ROUTE_BLUETOOTH));
+        bluetoothItem.setEnabled(isSupported(CallAudioStateCompat.ROUTE_BLUETOOTH));
         // TODO: Show bluetoothItem as initially "selected" if
         // bluetoothIndicatorOn is true.
 
diff --git a/InCallUI/src/com/android/incallui/CallButtonPresenter.java b/InCallUI/src/com/android/incallui/CallButtonPresenter.java
index b0adafd..5375b5b 100644
--- a/InCallUI/src/com/android/incallui/CallButtonPresenter.java
+++ b/InCallUI/src/com/android/incallui/CallButtonPresenter.java
@@ -16,23 +16,30 @@
 
 package com.android.incallui;
 
-import static com.android.incallui.CallButtonFragment.Buttons.*;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_ADD_CALL;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_AUDIO;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_DIALPAD;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_HOLD;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_MERGE;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_MUTE;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_PAUSE_VIDEO;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_SWAP;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_SWITCH_CAMERA;
+import static com.android.incallui.CallButtonFragment.Buttons.BUTTON_UPGRADE_TO_VIDEO;
 
 import android.content.Context;
 import android.os.Bundle;
-import android.telecom.CallAudioState;
 import android.telecom.InCallService.VideoCall;
 import android.telecom.VideoProfile;
 
+import com.android.dialer.compat.CallAudioStateCompat;
 import com.android.incallui.AudioModeProvider.AudioModeListener;
 import com.android.incallui.InCallCameraManager.Listener;
 import com.android.incallui.InCallPresenter.CanAddCallListener;
+import com.android.incallui.InCallPresenter.InCallDetailsListener;
 import com.android.incallui.InCallPresenter.InCallState;
 import com.android.incallui.InCallPresenter.InCallStateListener;
 import com.android.incallui.InCallPresenter.IncomingCallListener;
-import com.android.incallui.InCallPresenter.InCallDetailsListener;
-
-import java.util.Objects;
 
 /**
  * Logic for call buttons.
@@ -177,7 +184,7 @@
         // an update for onAudioMode().  This will make UI response immediate
         // if it turns out to be slow
 
-        Log.d(this, "Sending new Audio Mode: " + CallAudioState.audioRouteToString(mode));
+        Log.d(this, "Sending new Audio Mode: " + CallAudioStateCompat.audioRouteToString(mode));
         TelecomAdapter.getInstance().setAudioRoute(mode);
     }
 
@@ -186,7 +193,7 @@
      */
     public void toggleSpeakerphone() {
         // this function should not be called if bluetooth is available
-        if (0 != (CallAudioState.ROUTE_BLUETOOTH & getSupportedAudio())) {
+        if (0 != (CallAudioStateCompat.ROUTE_BLUETOOTH & getSupportedAudio())) {
 
             // It's clear the UI is wrong, so update the supported mode once again.
             Log.e(this, "toggling speakerphone not allowed when bluetooth supported.");
@@ -194,11 +201,11 @@
             return;
         }
 
-        int newMode = CallAudioState.ROUTE_SPEAKER;
+        int newMode = CallAudioStateCompat.ROUTE_SPEAKER;
 
         // if speakerphone is already on, change to wired/earpiece
-        if (getAudioMode() == CallAudioState.ROUTE_SPEAKER) {
-            newMode = CallAudioState.ROUTE_WIRED_OR_EARPIECE;
+        if (getAudioMode() == CallAudioStateCompat.ROUTE_SPEAKER) {
+            newMode = CallAudioStateCompat.ROUTE_WIRED_OR_EARPIECE;
         }
 
         setAudioMode(newMode);
diff --git a/InCallUI/src/com/android/incallui/InCallServiceImpl.java b/InCallUI/src/com/android/incallui/InCallServiceImpl.java
index 11202e7..3e4f714 100644
--- a/InCallUI/src/com/android/incallui/InCallServiceImpl.java
+++ b/InCallUI/src/com/android/incallui/InCallServiceImpl.java
@@ -23,6 +23,7 @@
 import android.telecom.CallAudioState;
 import android.telecom.InCallService;
 
+import com.android.dialer.compat.CallAudioStateCompat;
 import com.android.dialer.database.FilteredNumberAsyncQueryHandler;
 
 /**
@@ -33,9 +34,11 @@
  */
 public class InCallServiceImpl extends InCallService {
 
+    // TODO CallAudioState backporting blocked by InCallService backporting
     @Override
     public void onCallAudioStateChanged(CallAudioState audioState) {
-        AudioModeProvider.getInstance().onAudioStateChanged(audioState);
+        AudioModeProvider.getInstance().onAudioStateChanged(audioState.isMuted(),
+                audioState.getRoute(), audioState.getSupportedRouteMask());
     }
 
     @Override
diff --git a/InCallUI/src/com/android/incallui/ProximitySensor.java b/InCallUI/src/com/android/incallui/ProximitySensor.java
index 401ebd1..733a67d 100644
--- a/InCallUI/src/com/android/incallui/ProximitySensor.java
+++ b/InCallUI/src/com/android/incallui/ProximitySensor.java
@@ -16,20 +16,20 @@
 
 package com.android.incallui;
 
+import com.google.common.base.Objects;
+
 import android.content.Context;
 import android.content.res.Configuration;
 import android.hardware.display.DisplayManager;
 import android.hardware.display.DisplayManager.DisplayListener;
 import android.os.PowerManager;
-import android.telecom.CallAudioState;
 import android.view.Display;
 
+import com.android.dialer.compat.CallAudioStateCompat;
 import com.android.incallui.AudioModeProvider.AudioModeListener;
 import com.android.incallui.InCallPresenter.InCallState;
 import com.android.incallui.InCallPresenter.InCallStateListener;
 
-import com.google.common.base.Objects;
-
 /**
  * Class manages the proximity sensor for the in-call UI.
  * We enable the proximity sensor while the user in a phone call. The Proximity sensor turns off
@@ -228,9 +228,9 @@
         // turn proximity sensor off and turn screen on immediately if
         // we are using a headset, the keyboard is open, or the device
         // is being held in a horizontal position.
-            boolean screenOnImmediately = (CallAudioState.ROUTE_WIRED_HEADSET == audioMode
-                    || CallAudioState.ROUTE_SPEAKER == audioMode
-                    || CallAudioState.ROUTE_BLUETOOTH == audioMode
+            boolean screenOnImmediately = (CallAudioStateCompat.ROUTE_WIRED_HEADSET == audioMode
+                    || CallAudioStateCompat.ROUTE_SPEAKER == audioMode
+                    || CallAudioStateCompat.ROUTE_BLUETOOTH == audioMode
                     || mIsHardKeyboardOpen);
 
             // We do not keep the screen off when the user is outside in-call screen and we are
@@ -254,7 +254,7 @@
                     .add("offhook", mIsPhoneOffhook ? 1 : 0)
                     .add("hor", horizontal ? 1 : 0)
                     .add("ui", mUiShowing ? 1 : 0)
-                    .add("aud", CallAudioState.audioRouteToString(audioMode))
+                    .add("aud", CallAudioStateCompat.audioRouteToString(audioMode))
                     .toString());
 
             if (mIsPhoneOffhook && !screenOnImmediately) {