Ensure that we're reading the file from the start
@@ -387,6 +387,7 @@ class S3Boto3Storage(Storage):
def _compress_content(self, content):
"""Gzip a given string content."""
+ content.seek(0)
zbuf = BytesIO()
zfile = GzipFile(mode='wb', compresslevel=6, fileobj=zbuf)
try:
