diff --git a/src/main/java/com/nhn/pinpoint/bootstrap/PinpointURLClassLoader.java b/src/main/java/com/nhn/pinpoint/bootstrap/PinpointURLClassLoader.java
index a2fce9aaa..5119fd6f6 100644
--- a/src/main/java/com/nhn/pinpoint/bootstrap/PinpointURLClassLoader.java
+++ b/src/main/java/com/nhn/pinpoint/bootstrap/PinpointURLClassLoader.java
@@ -13,7 +13,7 @@ public class PinpointURLClassLoader extends URLClassLoader {
 
     private final ClassLoader parent;
 
-    private ProfilerLibClass profilerLibClass = new ProfilerLibClass();
+    private final ProfilerLibClass profilerLibClass = new ProfilerLibClass();
 
     public PinpointURLClassLoader(URL[] urls, ClassLoader parent) {
         super(urls, parent);