diff --git a/storage_s3/README.md b/storage_s3/README.md
index a7ac6f3..f38f970 100644
--- a/storage_s3/README.md
+++ b/storage_s3/README.md
@@ -15,12 +15,6 @@ to local storage (but it would of course be possible to write a script for this)
 
 ## Changelog
 
-### 3.1.1
-
-- Revert the fix from the previous version and replace it with one that's more reliable as
-  the problematic behavior seems to be caused by an nginx bug and the previous fix caused
-  failures in other cases
-
 ### 3.1
 
 - Fix "invalid signature" S3 error in some cases when using `proxy=nginx` for downloads
diff --git a/storage_s3/indico_storage_s3/storage.py b/storage_s3/indico_storage_s3/storage.py
index 1e80d99..be93de6 100644
--- a/storage_s3/indico_storage_s3/storage.py
+++ b/storage_s3/indico_storage_s3/storage.py
@@ -19,7 +19,6 @@ import boto3
 from boto3.s3.transfer import TransferConfig
 from botocore.config import Config
 from botocore.exceptions import ClientError
-from flask import request
 from werkzeug.datastructures import Headers
 from werkzeug.urls import url_quote
 from werkzeug.utils import cached_property, redirect
@@ -157,10 +156,7 @@ class S3StorageBase(Storage):
             if self.proxy_downloads == ProxyDownloadsMode.nginx:
                 # nginx can proxy the request to S3 to avoid exposing the redirect and
                 # bucket URL to the end user (since it is quite ugly and temporary)
-                nginx_url = url.replace('://', '/', 1)
-                if '%' not in request.base_url:
-                    nginx_url = url_quote(nginx_url)
-                response.headers['X-Accel-Redirect'] = f'/.xsf/s3/{nginx_url}'
+                response.headers['X-Accel-Redirect'] = '/.xsf/s3/' + url_quote(url.replace('://', '/', 1))
             return response
         except Exception as exc:
             raise StorageError(f'Could not send file "{file_id}": {exc}') from exc
diff --git a/storage_s3/setup.cfg b/storage_s3/setup.cfg
index 94012b4..0fbc8e9 100644
--- a/storage_s3/setup.cfg
+++ b/storage_s3/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = indico-plugin-storage-s3
-version = 3.1.1
+version = 3.1
 description = S3 storage backend for Indico
 long_description = file: README.md
 long_description_content_type = text/markdown; charset=UTF-8; variant=GFM