diff --git a/erpnext/accounts/doctype/account/chart_of_accounts/chart_of_accounts.py b/erpnext/accounts/doctype/account/chart_of_accounts/chart_of_accounts.py
index c7d1291..a5c551f 100644
--- a/erpnext/accounts/doctype/account/chart_of_accounts/chart_of_accounts.py
+++ b/erpnext/accounts/doctype/account/chart_of_accounts/chart_of_accounts.py
@@ -125,13 +125,14 @@
 	account_tree = {}
 
 	# fill in tree starting with root accounts (those with no parent)
-	build_account_tree(account_tree, None, all_accounts)
+	if all_accounts:
+		build_account_tree(account_tree, None, all_accounts)
 	return account_tree
 	
 def build_account_tree(tree, parent, all_accounts):
 	# find children
-	parent_account = parent.name if parent else None
-	children  = [acc for acc in all_accounts if acc.parent_account == parent_account]
+	parent_account = parent.name if parent else ""
+	children = [acc for acc in all_accounts if cstr(acc.parent_account) == parent_account]
 			
 	# if no children, but a group account
 	if not children and parent.is_group: