diff --git a/cvp_checks/utils/__init__.py b/cvp_checks/utils/__init__.py
index 7b1a2ab..840b4ea 100644
--- a/cvp_checks/utils/__init__.py
+++ b/cvp_checks/utils/__init__.py
@@ -73,6 +73,7 @@
 def calculate_groups():
     config = get_configuration()
     local_salt_client = init_salt_client()
+    node_groups = {}
     nodes_names = set ()
     expr_form = ''
     if 'groups' in config.keys():