diff --git a/main.py b/main.py
index dff1db1..703e959 100644
--- a/main.py
+++ b/main.py
@@ -62,7 +62,7 @@ def gen_groups_from_states(states):
     
     for state in states:
         for sheet in state['sheets'].values():
-            gr = sheet['groups']
+            gr = sheet.get('groups', {})
             if len(gr.keys()) == 0:
                 continue