diff --git a/java/src/com/android/inputmethod/research/LogUnit.java b/java/src/com/android/inputmethod/research/LogUnit.java
index c1258f496..839e2b7ba 100644
--- a/java/src/com/android/inputmethod/research/LogUnit.java
+++ b/java/src/com/android/inputmethod/research/LogUnit.java
@@ -16,7 +16,6 @@
 
 package com.android.inputmethod.research;
 
-import android.content.SharedPreferences;
 import android.os.SystemClock;
 import android.text.TextUtils;
 import android.util.JsonWriter;