diff --git a/java/src/com/android/inputmethod/keyboard/KeyboardView.java b/java/src/com/android/inputmethod/keyboard/KeyboardView.java
index 5827058..19f1fa8 100644
--- a/java/src/com/android/inputmethod/keyboard/KeyboardView.java
+++ b/java/src/com/android/inputmethod/keyboard/KeyboardView.java
@@ -1374,8 +1374,7 @@
         mHandler.cancelAllMessages();
 
         dismissPopupKeyboard();
-        mBuffer = null;
-        mCanvas = null;
+        mDirtyRect.union(0, 0, getWidth(), getHeight());
         mMiniKeyboardCache.clear();
         requestLayout();
     }