diff --git a/lbrynet/lbrynet_daemon/Publisher.py b/lbrynet/lbrynet_daemon/Publisher.py
index 7a6e73ee3..1836befbf 100644
--- a/lbrynet/lbrynet_daemon/Publisher.py
+++ b/lbrynet/lbrynet_daemon/Publisher.py
@@ -160,4 +160,4 @@ class Publisher(object):
 
 
 def get_content_type(filename):
-    return mimetypes.guess_type(filename)[0]
+    return mimetypes.guess_type(filename)[0] or 'application/octet-stream'