diff --git a/attract/cli.py b/attract/cli.py
index 4135eab..0083436 100644
--- a/attract/cli.py
+++ b/attract/cli.py
@@ -72,8 +72,9 @@ def setup_for_attract(project_url, replace=False):
     project = _get_project(project_url)
     permissions = copy.deepcopy(project['permissions'])
 
-    for perms in permissions.values():
+    for perms in (permissions['users'], permissions['groups']):
         for perm in perms:
+            assert isinstance(perm, dict), 'perm should be dict, but is %r' % perm
             methods = set(perm['methods'])
             if 'PUT' not in perm['methods']:
                 continue