diff --git a/s3_storage_provider.py b/s3_storage_provider.py
index 35b9bbd..ecfb074 100644
--- a/s3_storage_provider.py
+++ b/s3_storage_provider.py
@@ -50,12 +50,16 @@ class S3StorageProviderBackend(StorageProvider):
         self.cache_directory = hs.config.media_store_path
         self.bucket = config["bucket"]
         self.storage_class = config["storage_class"]
+        self.api_kwargs = {}
+        if "endpoint_url" in config:
+            self.api_kwargs["endpoint_url"] = config["endpoint_url"]
 
     def store_file(self, path, file_info):
         """See StorageProvider.store_file"""
 
         def _store_file():
-            boto3.resource('s3').Bucket(self.bucket).upload_file(
+            session = boto3.session.Session()
+            session.resource('s3', **self.api_kwargs).Bucket(self.bucket).upload_file(
                 Filename=os.path.join(self.cache_directory, path),
                 Key=path,
                 ExtraArgs={"StorageClass": self.storage_class},
@@ -68,7 +72,7 @@ class S3StorageProviderBackend(StorageProvider):
     def fetch(self, path, file_info):
         """See StorageProvider.fetch"""
         d = defer.Deferred()
-        _S3DownloadThread(self.bucket, path, d).start()
+        _S3DownloadThread(self.bucket, self.api_kwargs, path, d).start()
         return make_deferred_yieldable(d)
 
     @staticmethod
@@ -86,32 +90,39 @@ class S3StorageProviderBackend(StorageProvider):
         assert isinstance(bucket, string_types)
         assert storage_class in _VALID_STORAGE_CLASSES
 
-        return {
+        result = {
             "bucket": bucket,
             "storage_class": storage_class,
         }
 
+        if "endpoint_url" in config:
+            result["endpoint_url"] = config["endpoint_url"]
+
+        return result
+
 
 class _S3DownloadThread(threading.Thread):
     """Attempts to download a file from S3.
 
     Args:
         bucket (str): The S3 bucket which may have the file
+        api_kwargs (dict): Keyword arguments to pass when invoking the API. Generally `endpoint_url`.
         key (str): The key of the file
         deferred (Deferred[_S3Responder|None]): If file exists
             resolved with an _S3Responder instance, if it doesn't
             exist then resolves with None.
     """
 
-    def __init__(self, bucket, key, deferred):
+    def __init__(self, bucket, api_kwargs, key, deferred):
         super(_S3DownloadThread, self).__init__(name="s3-download")
         self.bucket = bucket
+        self.api_kwargs = api_kwargs
         self.key = key
         self.deferred = deferred
 
     def run(self):
         session = boto3.session.Session()
-        s3 = session.client('s3')
+        s3 = session.client('s3', **self.api_kwargs)
 
         try:
             resp = s3.get_object(Bucket=self.bucket, Key=self.key)