diff --git a/src/c3nav/site/urls.py b/src/c3nav/site/urls.py
index eb419b62..53eeacc3 100644
--- a/src/c3nav/site/urls.py
+++ b/src/c3nav/site/urls.py
@@ -2,7 +2,7 @@ from django.conf.urls import url
 
 from c3nav.site.views import map_index
 
-pos = r'(@(?P<level>[a-z0-9-_:]+),(?P<x>\d+(\.\d+)?),(?P<y>\d+(\.\d+)?),(?P<zoom>\d+(\.\d+)?))?'
+pos = r'(@(?P<level>[a-z0-9-_:]+),(?P<x>-?\d+(\.\d+)?),(?P<y>-?\d+(\.\d+)?),(?P<zoom>-?\d+(\.\d+)?))?'
 
 urlpatterns = [
     url(r'^r/(?P<origin>([a-z0-9-_:]+)?)/(?P<destination>([a-z0-9-_:]+)?)/%s$' % pos, map_index, name='site.index'),