diff -r fbf22ccd9d6f -r 0ee888c485d5 Hardware/SensorVisitor.cs
--- a/Hardware/SensorVisitor.cs	Tue Sep 21 10:33:28 2010 +0000
+++ b/Hardware/SensorVisitor.cs	Tue Sep 21 20:32:36 2010 +0000
@@ -41,7 +41,7 @@
 namespace OpenHardwareMonitor.Hardware {
 
   public class SensorVisitor : IVisitor {
-    private SensorEventHandler handler;
+    private readonly SensorEventHandler handler;
 
     public SensorVisitor(SensorEventHandler handler) {
       if (handler == null)