diff --git a/src/main/java/vip/jcfd/sdk/HGScannerWrapper.java b/src/main/java/vip/jcfd/sdk/HGScannerWrapper.java
index 8209087..95c6398 100644
--- a/src/main/java/vip/jcfd/sdk/HGScannerWrapper.java
+++ b/src/main/java/vip/jcfd/sdk/HGScannerWrapper.java
@@ -22,7 +22,7 @@ public class HGScannerWrapper {
     private static final Logger log = Logger.getLogger(HGScannerWrapper.class.getName());
 
     private static final int STRING_BUFFER_SIZE = 256;
-    private static HGScannerLib scannerLib;
+    private static final HGScannerLib scannerLib;
 
     static {
         NativeLibrary.addSearchPath("HGScannerLib", "C:/Program Files (x86)/HuaGoScannerLib/bin/x64");