diff --git a/posthog/client.py b/posthog/client.py
index 350871fc..82d5dec5 100644
--- a/posthog/client.py
+++ b/posthog/client.py
@@ -1997,7 +1997,7 @@ def _add_local_person_and_group_properties(
             for group_name in groups:
                 all_group_properties[group_name] = {
                     "$group_key": groups[group_name],
-                    **(group_properties.get(group_name) or {}),
+                    **((group_properties or {}).get(group_name) or {}),
                 }
 
         return all_person_properties, all_group_properties