diff --git a/java/src/com/android/inputmethod/keyboard/internal/GestureTrailsPreview.java b/java/src/com/android/inputmethod/keyboard/internal/GestureTrailsPreview.java
index d4c2594..19e9955 100644
--- a/java/src/com/android/inputmethod/keyboard/internal/GestureTrailsPreview.java
+++ b/java/src/com/android/inputmethod/keyboard/internal/GestureTrailsPreview.java
@@ -110,6 +110,7 @@
 
     private void freeOffscreenBuffer() {
         mOffscreenCanvas.setBitmap(null);
+        mOffscreenCanvas.setMatrix(null);
         if (mOffscreenBuffer != null) {
             mOffscreenBuffer.recycle();
             mOffscreenBuffer = null;