diff --git a/tcp_tests/helpers/ext.py b/tcp_tests/helpers/ext.py
index 5771eae..ca50c2e 100644
--- a/tcp_tests/helpers/ext.py
+++ b/tcp_tests/helpers/ext.py
@@ -24,8 +24,8 @@
     return collections.namedtuple('Enum', values)(*values)
 
 UNDERLAY_NODE_ROLE = enum(
-    'salt-master',
-    'salt-minion',
+    'salt_master',
+    'salt_minion',
 )
 
 NETWORK_TYPE = enum(