--- src/Lib/Network/SocketSet.hpp.old	2009-03-13 07:18:57.000000000 +0100
+++ src/Lib/Network/SocketSet.hpp	2009-03-13 07:19:24.000000000 +0100
@@ -62,10 +62,10 @@
     
 private:
     SOCKET maxfd;
-    fd_set readset;
-    fd_set writeset;
-    fd_set testreadset;
-    fd_set testwriteset;
+    mutable fd_set readset;
+    mutable fd_set writeset;
+    mutable fd_set testreadset;
+    mutable fd_set testwriteset;
 };
 
 }