diff --git a/src/pretix/settings.py b/src/pretix/settings.py
index 25193ca078..4a152eea4f 100644
--- a/src/pretix/settings.py
+++ b/src/pretix/settings.py
@@ -339,3 +339,7 @@ LOGGING = {
 
 CELERY_TASK_SERIALIZER = 'json'
 CELERY_RESULT_SERIALIZER = 'json'
+
+BOOTSTRAP3 = {
+    'success_css_class': ''
+}