diff --git a/library/build.gradle b/library/build.gradle
index c431e73f8..227c392f7 100755
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -38,7 +38,6 @@ android {
 dependencies {
     compile 'com.squareup.okhttp3:okhttp:3.2.0'
     compile 'com.qiniu:happy-dns:0.2.7'
-//    compile 'com.android.support:appcompat-v7:21.0.3'
     compile fileTree(include: ['*.jar'], dir: 'libs')
 }
 
diff --git a/library/src/main/java/com/qiniu/android/http/UserAgent.java b/library/src/main/java/com/qiniu/android/http/UserAgent.java
index 994ee7e91..4bc4a66e7 100644
--- a/library/src/main/java/com/qiniu/android/http/UserAgent.java
+++ b/library/src/main/java/com/qiniu/android/http/UserAgent.java
@@ -6,6 +6,7 @@
 import com.qiniu.android.common.Constants;
 import com.qiniu.android.utils.StringUtils;
 
+import java.nio.charset.Charset;
 import java.util.Locale;
 import java.util.Random;
 
@@ -72,7 +73,7 @@ private static String deviceName(String manufacturer, String model) {
     public String getUa(String part) {
         String _part = ("" + part).trim();
         _part = _part.substring(0, Math.min(16, _part.length()));
-        return ua + "; " + _part + ")";
+        return new String((ua + "; " + _part + ")").getBytes(Charset.forName("ISO-8859-1")));
     }
 
 }