--- duplicity/backends/webdavbackend.py        2019-11-02 16:05:00.000000000 +0100
+++ duplicity/backends/webdavbackend.py        2020-05-02 11:12:17.000000000 +0200
@@ -436,7 +436,7 @@
         url = self.directory + util.fsdecode(remote_filename)
         response = None
         try:
-            source_file = source_path.open(u"rb")
+            source_file = source_path.open(u"rb").read()
             response = self.request(u"PUT", url, source_file)
             # 200 is returned if a file is overwritten during restarting
             if response.status in [200, 201, 204]: