diff --git a/erpnext/patches/v4_0/global_defaults_to_system_settings.py b/erpnext/patches/v4_0/global_defaults_to_system_settings.py
index bbed172..fd6e47b 100644
--- a/erpnext/patches/v4_0/global_defaults_to_system_settings.py
+++ b/erpnext/patches/v4_0/global_defaults_to_system_settings.py
@@ -17,7 +17,7 @@
 	if global_defaults:
 		for key, val in global_defaults.items():
 			if not system_settings.get(key):
-				system_settings[key] = val
+				system_settings.set(key, val)
 
 	# language
 	if not system_settings.get("language"):