diff --git a/kwant/builder.py b/kwant/builder.py
index 15b303f390b3eb70a7c8805fbde16952632d3c7b..39689bff6c542321228094e01cd4c608d908c815 100644
--- a/kwant/builder.py
+++ b/kwant/builder.py
@@ -1004,9 +1004,7 @@ class Builder(object):
                 break
         else:
             msg = 'Sites with site families {0} do not appear in the system, ' \
-                'hence the system does not interrupt the lead. Note that ' \
-                'different lattice instances with the same parameters are ' \
-                'different site families. See tutorial for more details.'
+                'hence the system does not interrupt the lead.'
             raise ValueError(msg.format(tuple(families)))
 
         all_doms = list(sym.which(site)[0]