diff --git a/tryton-scripts/beitragsrechnungen.py b/tryton-scripts/beitragsrechnungen.py
index d4c9b92..4a5efc1 100644
--- a/tryton-scripts/beitragsrechnungen.py
+++ b/tryton-scripts/beitragsrechnungen.py
@@ -121,14 +121,14 @@ with triad.client.Session.start(args.url, args.username, args.password) as sessi
         try:
             monthly_fee = decimal.Decimal(member['monthly_fee'])
         except:
-            print(f"\tInvalid monthly fee: {member['monthly_fee']}", file=sys.stderr)
+            print(f"\tInvalid monthly fee: {member.get('monthly_fee')}", file=sys.stderr)
             monthly_fee = None
         else:
             print(f"\tMonthly fee: {monthly_fee}", file=sys.stderr)
         try:
             yearly_fee = decimal.Decimal(member['yearly_fee'])
         except:
-            print(f'\tInvalid yearly fee: {member['yearly_fee']}', file=sys.stderr)
+            print(f'\tInvalid yearly fee: {member.get("yearly_fee")}', file=sys.stderr)
             yearly_fee = None
         else:
             print(f'\tYearly fee: {yearly_fee}', file=sys.stderr)