diff --git a/packages/SystemUI/src/com/android/systemui/accessibility/WindowMagnification.java b/packages/SystemUI/src/com/android/systemui/accessibility/WindowMagnification.java
index 895207d..898cd13 100644
--- a/packages/SystemUI/src/com/android/systemui/accessibility/WindowMagnification.java
+++ b/packages/SystemUI/src/com/android/systemui/accessibility/WindowMagnification.java
@@ -17,6 +17,8 @@
 package com.android.systemui.accessibility;
 
 import android.content.Context;
+import android.content.pm.ActivityInfo;
+import android.content.res.Configuration;
 import android.database.ContentObserver;
 import android.os.Handler;
 import android.provider.Settings;
@@ -35,10 +37,25 @@
     private WindowMagnificationController mWindowMagnificationController;
     private final Handler mHandler;
 
+    private Configuration mLastConfiguration;
+
     @Inject
     public WindowMagnification(Context context, @Main Handler mainHandler) {
         super(context);
         mHandler = mainHandler;
+        mLastConfiguration = new Configuration(context.getResources().getConfiguration());
+    }
+
+    @Override
+    public void onConfigurationChanged(Configuration newConfig) {
+        final int configDiff = newConfig.diff(mLastConfiguration);
+        if ((configDiff & ActivityInfo.CONFIG_DENSITY) == 0) {
+            return;
+        }
+        mLastConfiguration.setTo(newConfig);
+        if (mWindowMagnificationController != null) {
+            mWindowMagnificationController.onConfigurationChanged(configDiff);
+        }
     }
 
     @Override
diff --git a/packages/SystemUI/src/com/android/systemui/accessibility/WindowMagnificationController.java b/packages/SystemUI/src/com/android/systemui/accessibility/WindowMagnificationController.java
index bfac4fc..c243309 100644
--- a/packages/SystemUI/src/com/android/systemui/accessibility/WindowMagnificationController.java
+++ b/packages/SystemUI/src/com/android/systemui/accessibility/WindowMagnificationController.java
@@ -113,6 +113,7 @@
         if (mMirrorView != null) {
             return;
         }
+        setInitialStartBounds();
         createOverlayWindow();
     }
 
@@ -178,9 +179,20 @@
         }
     }
 
-    private void createMirrorWindow() {
-        setInitialStartBounds();
+    /**
+     * Called when the configuration has changed, and it updates window magnification UI.
+     *
+     * @param configDiff a bit mask of the differences between the configurations
+     */
+    void onConfigurationChanged(int configDiff) {
+        // TODO(b/145780606): update toggle button UI.
+        if (mMirrorView != null) {
+            mWm.removeView(mMirrorView);
+            createMirrorWindow();
+        }
+    }
 
+    private void createMirrorWindow() {
         // The window should be the size the mirrored surface will be but also add room for the
         // border and the drag handle.
         int dragViewHeight = (int) mContext.getResources().getDimension(