diff --git a/image_creator/main.py b/image_creator/main.py
index af8f28ebcae32f15e2b0785078f71a78c297ce34..2f0bbb064f800ab368f366857df75f864a668c76 100644
--- a/image_creator/main.py
+++ b/image_creator/main.py
@@ -249,7 +249,7 @@ def image_creator():
             if options.upload:
                 out.output("Uploading image to pithos:")
                 kamaki = Kamaki(options.account, options.token, out)
-                with open(snapshot) as f:
+                with open(snapshot, 'rb') as f:
                     uploaded_obj = kamaki.upload(f, size, options.upload,
                                             "(1/4)  Calculating block hashes",
                                             "(2/4)  Uploading missing blocks")