diff --git a/src/pretix/api/views/exporters.py b/src/pretix/api/views/exporters.py
index c87893d2c5..a4823bd290 100644
--- a/src/pretix/api/views/exporters.py
+++ b/src/pretix/api/views/exporters.py
@@ -69,7 +69,7 @@ class ExportersMixin:
         cf = get_object_or_404(CachedFile, id=kwargs['cfid'])
         if cf.file:
             resp = ChunkBasedFileResponse(cf.file.file, content_type=cf.type)
-            resp['Content-Disposition'] = 'attachment; filename="{}"'.format(cf.filename)
+            resp['Content-Disposition'] = 'attachment; filename="{}"'.format(cf.filename).encode("ascii", "ignore")
             return resp
         elif not settings.HAS_CELERY:
             return Response(
diff --git a/src/pretix/base/views/cachedfiles.py b/src/pretix/base/views/cachedfiles.py
index b95e5ab7e4..c0690a475d 100644
--- a/src/pretix/base/views/cachedfiles.py
+++ b/src/pretix/base/views/cachedfiles.py
@@ -47,7 +47,7 @@ class DownloadView(TemplateView):
             return HttpResponse('1' if self.object.file else '0')
         elif self.object.file:
             resp = ChunkBasedFileResponse(self.object.file.file, content_type=self.object.type)
-            resp['Content-Disposition'] = 'attachment; filename="{}"'.format(self.object.filename)
+            resp['Content-Disposition'] = 'attachment; filename="{}"'.format(self.object.filename).encode('ascii', 'ignore')
             return resp
         else:
             return super().get(request, *args, **kwargs)
diff --git a/src/pretix/presale/views/cart.py b/src/pretix/presale/views/cart.py
index b1be0668f2..8e05a98160 100644
--- a/src/pretix/presale/views/cart.py
+++ b/src/pretix/presale/views/cart.py
@@ -661,5 +661,5 @@ class AnswerDownload(EventViewMixin, View):
         resp['Content-Disposition'] = 'attachment; filename="{}-cart-{}"'.format(
             self.request.event.slug.upper(),
             os.path.basename(answer.file.name).split('.', 1)[1]
-        )
+        ).encode("ascii", "ignore")
         return resp