diff --git a/web/controller.py b/web/controller.py
index 2275733..5320d6e 100644
--- a/web/controller.py
+++ b/web/controller.py
@@ -7,7 +7,8 @@ import cherrypy
 
 from web.model import latest_per_day, \
                       build_centerpkg_list, \
-                      get_atom
+                      get_atom, \
+                      NotValidAtom
 from web.lib.headers import lastmodified_httpheader, \
                             lastmodified_rightcontent
 from web.lib.query_filter import sanitize_query_string
@@ -380,7 +381,11 @@ class Root(object):
             cat = args[0]
             pn = args[1]
             cpvstr = '%s/%s' % (cat, pn)
-            cpvtmp = get_atom(cpvstr)
+            try:
+                cpvtmp = get_atom(cpvstr)
+            except NotValidAtom:
+                raise cherrypy.HTTPRedirect("/")
+             
             pn = cpvtmp.package
             cat = cpvtmp.category
             pagetitle = "/package/%s/%s" % (cat, pn)
diff --git a/web/model.py b/web/model.py
index 68ce012..97c4f1d 100644
--- a/web/model.py
+++ b/web/model.py
@@ -20,6 +20,12 @@ from web.lib.links import   viewcvs_link, \
 # We use short variable names!
 # pylint: disable-msg=C0103
 
+class NotValidAtom(Exception):
+    def __init__(self, value):
+         self.value = value
+    def __str__(self):
+         return repr('Not a valid package atom at all: %s' % self.value)
+
 def get_atom(cpvstr):
     """Nasty hack to work around not knowing if an atom is versioned or not"""
     v_atom = u_atom = None
@@ -41,7 +47,7 @@ def get_atom(cpvstr):
     if u_atom:
         return u_atom 
 
-    raise Exception('Not a valid package atom at all: %s' % (cpvstr))
+    raise NotValidAtom(cpvstr)
 
 def caller_name():
     """Return the name of the function that this was called from"""