diff --git a/app/build.gradle b/app/build.gradle
index df4e97f..0f46040 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -37,7 +37,7 @@ android {
     buildTypes {
         release {
 	    signingConfig signingConfigs.release
-            minifyEnabled true
+            minifyEnabled false
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
         debug {
diff --git a/app/src/main/java/thercn/wmw/FileUtils.java b/app/src/main/java/thercn/wmw/FileUtils.java
index ed51eb4..891c46b 100644
--- a/app/src/main/java/thercn/wmw/FileUtils.java
+++ b/app/src/main/java/thercn/wmw/FileUtils.java
@@ -2,7 +2,6 @@
 
 import java.io.File;
 import java.io.IOException;
-import android.os.FileUtils;
 
 public class FileUtils {
 	public static boolean createFile(String filePath, boolean isDir) throws IOException