diff --git a/src/pretix/base/forms/__init__.py b/src/pretix/base/forms/__init__.py
index 77fb0fcc27..b67ee403b3 100644
--- a/src/pretix/base/forms/__init__.py
+++ b/src/pretix/base/forms/__init__.py
@@ -5,6 +5,7 @@ import os
 from django import forms
 from django.conf import settings
 from django.core.files import File
+from django.core.files.storage import default_storage
 from django.core.files.uploadedfile import UploadedFile
 from django.db import models
 from django.forms.models import BaseModelForm, ModelFormMetaclass
@@ -105,8 +106,7 @@ class SettingsForm(forms.Form):
                     )
                 else:
                     fname = '%s/%s.%s' % (self.obj.slug, name, value.name.split('.')[-1])
-                fpath = os.path.join(settings.MEDIA_ROOT, fname)
-                with open(fpath, 'wb+') as destination:
+                with default_storage.open(fname, 'wb+') as destination:
                     for chunk in value.chunks():
                         destination.write(chunk)
                 value._name = fname
@@ -118,7 +118,7 @@ class SettingsForm(forms.Form):
                 fname = self.obj.settings.get(name, as_type=File)
                 if fname:
                     try:
-                        os.unlink(fname.name)
+                        default_storage.delete(fname.name)
                     except OSError:
                         logger.error('Deleting file %s failed.' % fname.name)
 
diff --git a/src/pretix/base/settings.py b/src/pretix/base/settings.py
index f26c425ed3..7b3f8224c0 100644
--- a/src/pretix/base/settings.py
+++ b/src/pretix/base/settings.py
@@ -7,6 +7,7 @@ from urllib.parse import urljoin
 import dateutil.parser
 from django.conf import settings
 from django.core.files import File
+from django.core.files.storage import default_storage
 from django.db.models import Model
 from versions.models import Versionable
 
@@ -139,9 +140,8 @@ class SettingsProxy:
             return value == 'True'
         elif as_type == File:
             try:
-                f = open(os.path.join(settings.MEDIA_ROOT, value[7:]), 'r')
-                fi = File(f)
-                fi.url = urljoin(settings.MEDIA_URL, value[7:])
+                fi = default_storage.open(value[7:], 'r')
+                fi.url = default_storage.url(value[7:])
                 return fi
             except OSError:
                 return False
diff --git a/src/pretix/plugins/ticketoutputpdf/ticketoutput.py b/src/pretix/plugins/ticketoutputpdf/ticketoutput.py
index ecadd11a6d..292565ce25 100644
--- a/src/pretix/plugins/ticketoutputpdf/ticketoutput.py
+++ b/src/pretix/plugins/ticketoutputpdf/ticketoutput.py
@@ -5,6 +5,7 @@ from io import BytesIO
 from django import forms
 from django.contrib.staticfiles import finders
 from django.core.files import File
+from django.core.files.storage import default_storage
 from django.http import HttpResponse
 from django.utils.translation import ugettext_lazy as _
 
@@ -37,12 +38,6 @@ class PdfTicketOutput(BaseTicketOutput):
         if hasattr(pagesizes, orientation):
             pagesize = getattr(pagesizes, orientation)(pagesize)
 
-        fname = self.settings.get('background', as_type=File)
-        if isinstance(fname, File):
-            fname = fname.name
-        else:
-            fname = finders.find('pretixpresale/pdf/ticket_default_a4.pdf')
-
         buffer = BytesIO()
         p = canvas.Canvas(buffer, pagesize=pagesize)
 
@@ -98,11 +93,17 @@ class PdfTicketOutput(BaseTicketOutput):
         buffer.seek(0)
         new_pdf = PdfFileReader(buffer)
         output = PdfFileWriter()
+        bg_file = self.settings.get('background', as_type=File)
+        if isinstance(bg_file, File):
+            new_bg_file = lambda: default_storage.open(bg_file.name, "rb")
+        else:
+            new_bg_file = lambda: open(finders.find('pretixpresale/pdf/ticket_default_a4.pdf'), "rb")
         for page in new_pdf.pages:
-            bg_pdf = PdfFileReader(open(fname, "rb"))
-            bg_page = bg_pdf.getPage(0)
-            bg_page.mergePage(page)
-            output.addPage(bg_page)
+            with new_bg_file() as bgf:
+                bg_pdf = PdfFileReader(bgf)
+                bg_page = bg_pdf.getPage(0)
+                bg_page.mergePage(page)
+                output.addPage(bg_page)
 
         outbuffer = BytesIO()
         output.write(outbuffer)