diff --git a/src/pretix/plugins/banktransfer/tasks.py b/src/pretix/plugins/banktransfer/tasks.py
index 908d3dbc4c..00344754e4 100644
--- a/src/pretix/plugins/banktransfer/tasks.py
+++ b/src/pretix/plugins/banktransfer/tasks.py
@@ -84,13 +84,13 @@ def _handle_transaction(trans: BankTransaction, matches: tuple, event: Event = N
     if event:
         for slug, code in matches:
             order = _find_order_for_code(event.orders, code)
-            if order:
+            if order and order.code not in {o.code for o in orders}:
                 orders.append(order)
     else:
         qs = Order.objects.filter(event__organizer=organizer)
         for slug, code in matches:
             order = _find_order_for_code(qs.filter(event__slug__iexact=slug), code)
-            if order:
+            if order and order.code not in {o.code for o in orders}:
                 orders.append(order)
 
     if not orders:
diff --git a/src/tests/plugins/banktransfer/test_import.py b/src/tests/plugins/banktransfer/test_import.py
index acc7ba86fa..3422f16fee 100644
--- a/src/tests/plugins/banktransfer/test_import.py
+++ b/src/tests/plugins/banktransfer/test_import.py
@@ -260,6 +260,18 @@ def test_mark_paid_organizer(env, orga_job):
     assert env[2].status == Order.STATUS_PAID
 
 
+@pytest.mark.django_db
+def test_mark_paid_double_reference(env, orga_job):
+    process_banktransfers(orga_job, [{
+        'payer': 'Karla Kundin',
+        'reference': 'Bestellung DUMMY-1234S DUMMY-1234S',
+        'date': '2016-01-26',
+        'amount': '23.00'
+    }])
+    env[2].refresh_from_db()
+    assert env[2].status == Order.STATUS_PAID
+
+
 @pytest.mark.django_db
 def test_mark_paid_organizer_dash_in_slug(env, orga_job):
     env[0].slug = "foo-bar"