diff --git a/fmartingrcom/utils.py b/fmartingrcom/utils.py
index dda18c2..62f2df9 100644
--- a/fmartingrcom/utils.py
+++ b/fmartingrcom/utils.py
@@ -10,6 +10,7 @@ def sha1_checksum(handler):
         temp_name = '/tmp/_{}'.format(uuid.uuid4())
         f = open(temp_name, 'wb+')
         f.write(handler.read())
+        f.seek(0)
     else:
         f = open(handler.name, 'rb')