fix node roles
diff --git a/tcp_tests/helpers/ext.py b/tcp_tests/helpers/ext.py
index ca50c2e..5369535 100644
--- a/tcp_tests/helpers/ext.py
+++ b/tcp_tests/helpers/ext.py
@@ -23,7 +23,7 @@
         return collections.namedtuple('Enum', names)(*values)
     return collections.namedtuple('Enum', values)(*values)
 
-UNDERLAY_NODE_ROLE = enum(
+UNDERLAY_NODE_ROLES = enum(
     'salt_master',
     'salt_minion',
 )