diff --git a/mpmaster/src/main/java/com/xypower/mpmaster/MpMasterService.java b/mpmaster/src/main/java/com/xypower/mpmaster/MpMasterService.java
index 75965a94..84b06a40 100644
--- a/mpmaster/src/main/java/com/xypower/mpmaster/MpMasterService.java
+++ b/mpmaster/src/main/java/com/xypower/mpmaster/MpMasterService.java
@@ -42,6 +42,7 @@ import com.xypower.mpmaster.sms.SmsSendReceiver;
 import org.json.JSONObject;
 
 import java.io.File;
+import java.util.List;
 import java.util.logging.FileHandler;
 import java.util.logging.Level;
 import java.util.logging.Logger;