diff --git a/fas/fas/group.py b/fas/fas/group.py
index 5b820ea..03c9af6 100644
--- a/fas/fas/group.py
+++ b/fas/fas/group.py
@@ -39,7 +39,7 @@ class GroupCreate(validators.Schema):
     name = validators.All(
         UnknownGroup,
         validators.String(max=32, min=3),
-        validators.Regex(regex='^[a-z0-9\-]+$'),
+        validators.Regex(regex='^[a-z0-9\-_]+$'),
         )
     display_name = validators.NotEmpty
     owner = validators.All(