--- a/pvl/verkko/rrd.py	Mon Jan 21 18:11:35 2013 +0200
+++ b/pvl/verkko/rrd.py	Mon Jan 21 18:13:06 2013 +0200
@@ -148,7 +148,7 @@
             self.target = target
 
         except ValueError as ex :
-            raise web.NotFound(tree + '/' + target)
+            raise web.NotFound((tree, target))
 
     def render_interval (self, interval, style='detail') :
         """
@@ -189,7 +189,7 @@
             self.rrd = self.app.rrd.rrd(target, self.tree)
 
         except ValueError as ex :
-            raise web.NotFound(tree + '/' + target)
+            raise web.NotFound((tree, target))
         
         self.style = style
         self.interval = interval