Working on IO loop stuff.
diff --git a/utils/nio/src/main/java/org/onlab/nio/AcceptorLoop.java b/utils/nio/src/main/java/org/onlab/nio/AcceptorLoop.java
index a5acc41..785dbf9 100644
--- a/utils/nio/src/main/java/org/onlab/nio/AcceptorLoop.java
+++ b/utils/nio/src/main/java/org/onlab/nio/AcceptorLoop.java
@@ -28,7 +28,7 @@
     public AcceptorLoop(long selectTimeout, SocketAddress listenAddress)
             throws IOException {
         super(selectTimeout);
-        this.listenAddress = checkNotNull(this.listenAddress, "Address cannot be null");
+        this.listenAddress = checkNotNull(listenAddress, "Address cannot be null");
     }
 
     /**