diff --git a/src/pretix/control/forms/modelimport.py b/src/pretix/control/forms/modelimport.py
index c96cf29c49..27417cee2e 100644
--- a/src/pretix/control/forms/modelimport.py
+++ b/src/pretix/control/forms/modelimport.py
@@ -21,6 +21,8 @@
 #
 from django import forms
 from django.core.exceptions import ValidationError
+from django.utils.functional import lazy
+from django.utils.html import format_html
 from django.utils.translation import gettext_lazy as _
 
 from pretix.base.modelimport_orders import get_order_import_columns
@@ -71,6 +73,9 @@ class ProcessForm(forms.Form):
         raise NotImplementedError()  # noqa
 
 
+format_html_lazy = lazy(format_html, str)
+
+
 class OrdersProcessForm(ProcessForm):
     orders = forms.ChoiceField(
         label=_('Import mode'),
@@ -91,7 +96,11 @@ class OrdersProcessForm(ProcessForm):
     )
     testmode = forms.BooleanField(
         label=_('Create orders as test mode orders'),
-        required=False
+        required=False,
+        help_text=format_html_lazy(
+            '<div class="alert alert-warning" data-display-dependency="#id_testmode" data-inverse>{}</div>',
+            _('Orders not created in test mode cannot be deleted again after import.')
+        )
     )
 
     def __init__(self, *args, **kwargs):
@@ -100,6 +109,8 @@ class OrdersProcessForm(ProcessForm):
         initital['testmode'] = self.event.testmode
         kwargs['initial'] = initital
         super().__init__(*args, **kwargs)
+        if not self.event.testmode:
+            self.fields["testmode"].help_text = ""
 
     def get_columns(self):
         return get_order_import_columns(self.event)