diff --git a/seminar/urls.py b/seminar/urls.py
index f066a0b3..4890a6ba 100644
--- a/seminar/urls.py
+++ b/seminar/urls.py
@@ -8,7 +8,7 @@ urlpatterns = patterns('',
     url(r'^archiv/cisla/$', views.CislaView.as_view()),
 
     url(r'^rocnik/(?P<rocnik>\d+)/$', views.RocnikView.as_view(), name='seminar_rocnik'),
-    url(r'^cislo/(?P<rocnik>\d+)\.(?P<cislo>\d+)/$', views.CisloView.as_view(), name='seminar_cislo'),
+    url(r'^cislo/(?P<rocnik>\d+)\.(?P<cislo>[0-9-]+)/$', views.CisloView.as_view(), name='seminar_cislo'),
     url(r'^problem/(?P<pk>\d+)/$', views.ProblemView.as_view(), name='seminar_problem'),
 
     url(r'^soustredeni/$', views.SoustredeniListView.as_view(),