diff --git a/handler/lib/serde/nordigen.py b/handler/lib/serde/nordigen.py
index 3c0e738..ac0e2a6 100644
--- a/handler/lib/serde/nordigen.py
+++ b/handler/lib/serde/nordigen.py
@@ -117,7 +117,7 @@ class AccountBalances(Model):
 
 
 class AccountBalancesRoot(Model):
-    balances = fields.List(AccountBalances)
+    balances = fields.Optional(fields.List(AccountBalances))
 
 
 class RequisitionResponse(Model):