diff --git a/addons/account_extra_reports/report/account_partner_ledger.py b/addons/account_extra_reports/report/account_partner_ledger.py
index a5ca5ed2a3c..12ddab4e451 100644
--- a/addons/account_extra_reports/report/account_partner_ledger.py
+++ b/addons/account_extra_reports/report/account_partner_ledger.py
@@ -28,9 +28,9 @@ class ReportPartnerLedger(models.AbstractModel):
         sum = 0.0
         for r in res:
             r['displayed_name'] = '-'.join(
-                r['move_name'] not in ['', '/'] and [r['move_name']] or [] +
-                r['ref'] not in ['', '/'] and [r['ref']] or [] +
-                r['name'] not in ['', '/'] and [r['name']] or []
+                    (r['move_name'] not in ['', '/'] and [r['move_name']] or []) +
+                    (r['ref'] not in ['', '/'] and [r['ref']] or []) +
+                    (r['name'] not in ['', '/'] and [r['name']] or [])
                 )
             sum += r['debit'] - r['credit']
             r['progress'] = sum