diff --git a/common/src/main/java/io/netty/util/concurrent/DefaultThreadFactory.java b/common/src/main/java/io/netty/util/concurrent/DefaultThreadFactory.java
index bab2cf9c73..c0c56bf1b2 100644
--- a/common/src/main/java/io/netty/util/concurrent/DefaultThreadFactory.java
+++ b/common/src/main/java/io/netty/util/concurrent/DefaultThreadFactory.java
@@ -34,7 +34,7 @@ public class DefaultThreadFactory implements ThreadFactory {
     private final String prefix;
     private final boolean daemon;
     private final int priority;
-    private final ThreadGroup threadGroup;
+    protected final ThreadGroup threadGroup;
 
     public DefaultThreadFactory(Class<?> poolType) {
         this(poolType, false, Thread.NORM_PRIORITY);