diff --git a/opentech/storage_backends.py b/opentech/storage_backends.py
index 2acf70c958d34c4c682f33f0e22b363f285ff525..82b84f92e8841537b8435b66a47f73a51e4c22bb 100644
--- a/opentech/storage_backends.py
+++ b/opentech/storage_backends.py
@@ -35,7 +35,7 @@ class PrivateMediaStorage(S3Boto3Storage):
         if hasattr(settings, 'AWS_PRIVATE_CUSTOM_DOMAIN'):
             # Django storage doesn't handle custom domains with auth strings
             custom_domain = settings.AWS_PRIVATE_CUSTOM_DOMAIN
-            parts = list(url.split(url))
+            parts = list(parse.urlsplit(url))
             parts[0:3] = self.url_protocol, custom_domain, filepath_to_uri(name)
             return parse.urlunsplit(parts)