diff --git a/s3_storage_provider.py b/s3_storage_provider.py
index bb97c66..8cd9482 100644
--- a/s3_storage_provider.py
+++ b/s3_storage_provider.py
@@ -54,7 +54,8 @@ class S3StorageProviderBackend(StorageProvider):
         """See StorageProvider.store_file"""
 
         def _store_file():
-            boto3.resource('s3', **self.api_kwargs).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},